Simulation Tutorials

Contents

Chapter 1 Part Modal and Stress Analysis . . . . . . . . . . . . . . . . . . . 1Simulation 1: About this tutorial . . . . . . . . . . . . . . . . . . . . . . 1Open the Model for Modal Analysis . . . . . . . . . . . . . . . . . . . . 3Enter the Stress Analysis Environment . . . . . . . . . . . . . . . . . . . 3Assign Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Add Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Preview Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Run Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7View the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Simulation 2: About this tutorial . . . . . . . . . . . . . . . . . . . . . 12Copy Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Create Parametric Geometry . . . . . . . . . . . . . . . . . . . . . . . 14Include Optimization Criteria . . . . . . . . . . . . . . . . . . . . . . . 16Add Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Set Convergence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Run Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18View the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Chapter 2 Assembly Stress Analysis . . . . . . . . . . . . . . . . . . . . . 23About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Get Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

i

Stress Analysis Environment . . . . . . . . . . . . . . . . . . . . . . . 25Excluding Components . . . . . . . . . . . . . . . . . . . . . . . . . . 26Assign Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Add Constraints and Loads . . . . . . . . . . . . . . . . . . . . . . . . 28Stress Analysis Settings . . . . . . . . . . . . . . . . . . . . . . . . . . 31Contact Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Generate Meshes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34View and Interpret the Results . . . . . . . . . . . . . . . . . . . . . . 35Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 3 Contacts and Mesh Refinement . . . . . . . . . . . . . . . . . 39About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Open the Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Stress Analysis Environment . . . . . . . . . . . . . . . . . . . . . . . 41Create a Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Exclude Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Assign Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Add Constraints and Loads . . . . . . . . . . . . . . . . . . . . . . . . 43Define Contact Conditions . . . . . . . . . . . . . . . . . . . . . . . . 46Specify and Preview Meshes . . . . . . . . . . . . . . . . . . . . . . . . 50Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51View and Interpret the Results . . . . . . . . . . . . . . . . . . . . . . 51Copy and Modify Simulation . . . . . . . . . . . . . . . . . . . . . . . 54Specify Local Mesh Controls . . . . . . . . . . . . . . . . . . . . . . . 54Run the Simulation Again . . . . . . . . . . . . . . . . . . . . . . . . . 56View and Interpret the Results Again . . . . . . . . . . . . . . . . . . . 57Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Chapter 4 Assembly Modal Analysis . . . . . . . . . . . . . . . . . . . . . 61About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Create a Simulation Study . . . . . . . . . . . . . . . . . . . . . . . . . 65Exclude Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Assign Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Add Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Create Manual Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . 68Specify Mesh Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Preview Mesh and Run Simulation . . . . . . . . . . . . . . . . . . . . 70View and Interpret Results . . . . . . . . . . . . . . . . . . . . . . . . 71Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Chapter 5 FEA Assembly Optimization . . . . . . . . . . . . . . . . . . . . 75About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

ii | Contents

Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Define the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Assign Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78Adding Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78Adding Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79Modify the Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80Preview the Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81Create Parametric Geometry . . . . . . . . . . . . . . . . . . . . . . . 82Optimization Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . 84Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85View and Interpret the Results . . . . . . . . . . . . . . . . . . . . . . 85View and animate 3D plots . . . . . . . . . . . . . . . . . . . . . . . . 87View XY Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Chapter 6 Stress Analysis Contacts . . . . . . . . . . . . . . . . . . . . . . 93About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94How a Caulk Gun Works . . . . . . . . . . . . . . . . . . . . . . . . . 96Assembly Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 99Contact Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Bonded Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102Separation Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Sliding and No Separation Contact . . . . . . . . . . . . . . . . . . . 104Separation and No Sliding Contact . . . . . . . . . . . . . . . . . . . 107Shrink Fit and No Sliding Contact . . . . . . . . . . . . . . . . . . . . 108Spring Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110Loads and Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . 111Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Chapter 7 Frame Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 117About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 119Frame Analysis Environment . . . . . . . . . . . . . . . . . . . . . . 119Frame Analysis Settings . . . . . . . . . . . . . . . . . . . . . . . . . 122Assign Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122Change Beam Properties . . . . . . . . . . . . . . . . . . . . . . . . . 124Change Direction of Gravity . . . . . . . . . . . . . . . . . . . . . . . 124Add Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125Add Constraints to the Next Beam . . . . . . . . . . . . . . . . . . . 128Add Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 131View and Interpret Results . . . . . . . . . . . . . . . . . . . . . . . . 132

Contents | iii

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Chapter 8 Frame Analysis Results . . . . . . . . . . . . . . . . . . . . . . 135About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135Get Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136Frame Analysis Environment . . . . . . . . . . . . . . . . . . . . . . 137View and Interpret the Results . . . . . . . . . . . . . . . . . . . . . . 139Display Maximum and Minimum Values . . . . . . . . . . . . . . . . 140View Beam Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141Display and Edit Diagrams . . . . . . . . . . . . . . . . . . . . . . . . 142Adjust Displacement Display . . . . . . . . . . . . . . . . . . . . . . 144Animate the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 146Generate Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Chapter 9 Frame Analysis Connections . . . . . . . . . . . . . . . . . . . 149About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149Connections Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 150Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 151Frame Analysis Environment . . . . . . . . . . . . . . . . . . . . . . 152Change Direction of Gravity . . . . . . . . . . . . . . . . . . . . . . . 154Add Custom Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Add Custom Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . 157Change Color of Custom Nodes . . . . . . . . . . . . . . . . . . . . . 159Assign Rigid Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Add Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 165View the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166Assign a Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167Run the Simulation Again . . . . . . . . . . . . . . . . . . . . . . . . 169View the Updated Results . . . . . . . . . . . . . . . . . . . . . . . . 170Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Chapter 10 Modal Type of Frame Analysis . . . . . . . . . . . . . . . . . . 173About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 175Frame Analysis Environment . . . . . . . . . . . . . . . . . . . . . . 175Create a Simulation Study . . . . . . . . . . . . . . . . . . . . . . . . 175Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 176View the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177Animate the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 178Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Chapter 11 Dynamic Simulation - Part 1 . . . . . . . . . . . . . . . . . . . 181

iv | Contents

About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181Open the Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 182Degrees of Freedom . . . . . . . . . . . . . . . . . . . . . . . . . . . 183Automatic Constraint Conversion . . . . . . . . . . . . . . . . . . . . 184Assembly Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . 187Add a Rolling Joint . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189Building a 2D Contact . . . . . . . . . . . . . . . . . . . . . . . . . . 190Add Spring, Damper, and Jack Joint . . . . . . . . . . . . . . . . . . . 193Define Gravity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195Impose Motion on a Joint . . . . . . . . . . . . . . . . . . . . . . . . 196Run a Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197Using the Output Grapher . . . . . . . . . . . . . . . . . . . . . . . . 198Simulation Player . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

Chapter 12 Dynamic Simulation - Part 2 . . . . . . . . . . . . . . . . . . . 205About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205Work in the Simulation Environment . . . . . . . . . . . . . . . . . . 206Construct the Operating Conditions . . . . . . . . . . . . . . . . . . 208Add Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210Add a Sliding Joint . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212Use the Input Grapher . . . . . . . . . . . . . . . . . . . . . . . . . . 213Use the Output Grapher . . . . . . . . . . . . . . . . . . . . . . . . . 217Export to FEA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Publish Output in Inventor Studio . . . . . . . . . . . . . . . . . . . 223Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

Chapter 13 Assembly Motion and Loads . . . . . . . . . . . . . . . . . . . 227About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227Open Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229Activate Dynamic Simulation . . . . . . . . . . . . . . . . . . . . . . 231Automatic Joint Creation . . . . . . . . . . . . . . . . . . . . . . . . 231Define Gravity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232Insert a Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232Define the Spring Properties . . . . . . . . . . . . . . . . . . . . . . . 235Run the Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 236Insert a Contact Joint . . . . . . . . . . . . . . . . . . . . . . . . . . 237Edit the Joint Properties . . . . . . . . . . . . . . . . . . . . . . . . . 239Add Imposed Motion . . . . . . . . . . . . . . . . . . . . . . . . . . 241View the Simulation Results . . . . . . . . . . . . . . . . . . . . . . . 241View the Simulation Results (continued) . . . . . . . . . . . . . . . . 242Export the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

Contents | v

Chapter 14 FEA using Motion Loads . . . . . . . . . . . . . . . . . . . . . 245About this tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246Open Assembly File . . . . . . . . . . . . . . . . . . . . . . . . . . . 247Run a Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249Generate Time Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . 249Export to Stress Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 249Use the Motion Loads in Stress Analysis . . . . . . . . . . . . . . . . . 253Generate a report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

vi | Contents

Part Modal and StressAnalysis

Simulation 1: About this tutorial

Modal analysis.

SimulationCategory

20 minutesTime Required

1

1

PivotBracket.iptTutorial FilesUsed

You will create two simulations: modal analysis of the part and a parametricstructural static analysis on the same part.

The Modal Analysis tutorial walks through the process of defining andperforming a structural frequency analysis, or modal analysis, for a part. Thesimulation generates the natural frequencies (Eigenvalues) and correspondingmode shapes which we view and interpret at the end of the tutorial.

The second simulation is a parametric study on the same model. Parametricstudies vary the design parameters to update geometry and evaluate variousconfigurations for a design case. We perform a structural static analysis withthe goal of minimizing model weight.

Objectives■ Create a simulation for modal analysis

■ Override the model material with a different material

■ Specify constraints

■ Run the simulation

■ View and interpret the results

Prerequisites■ Familiarity with the ribbon user interface and Quick Access Toolbar.

■ Familiarity with the use of the model browser and context menus.

■ See the Help topic “Getting Started” for further information.

Navigation Tips■ Use Show in the upper-left corner to display the table of contents for this

tutorial with navigation links to each page.

■ Use Forward in the upper-right corner to advance to the next page.

Next (page 3)

2 | Chapter 1 Part Modal and Stress Analysis

Open the Model for Modal AnalysisLet’s get started on the Modal Analysis simulation first.

1 On the Quick Access Toolbar, click the Open command.

2 Set your project file to Tutorial_Files.ipj if not already set.

3 Select the part model named PivotBracket.ipt.

4 Click Open.

Previous (page 1) | Next (page 3)

Enter the Stress Analysis EnvironmentThe stress analysis environment is one of a handful of Inventor environmentsthat enable specialized activity relative to the model. In this case, itincorporates commands for doing part and assembly stress analysis.

To enter the stress analysis environment and start a simulation:

1 Click the Environments tab in the ribbon bar. The list of availableenvironments is presented.

2 Click the Stress Analysis environment command.

3 Click Create Simulation.

4 The Create New Simulation dialog box displays. Specify the name ModalAnalysis.

5 In the Simulation Type tab, select Modal Analysis.

6 Leave the remaining settings in their current state and click OK. A newsimulation is started and the browser is populated with stressanalysis-related folders.


Open the Model for Modal Analysis | 3

Assign MaterialFor any component that you want to analyze, check the material to make surethat it is defined. Some Inventor materials do not have “simulation-ready”properties and need modification before using them in simulations. If youuse an inadequately defined material, a message displays. Modify the materialor select another material.

You can use different materials in different simulations and compare theresults in a report. To assign a different material:

1 In the ribbon bar, in the Material panel, click Assign Materials.

2 Click in the Override Material column to activate the drop-down list.

3 Select Aluminum-6061.

4 Click OK.

NOTE Use the Styles and Standards Editor to modify materials if they are notcompletely defined. You can access the editor from the lower left corner of theAssign Materials dialog box.


Add ConstraintsNext, we add the boundary conditions, a single constraint on the interiorcylindrical face.

To add the constraint:

1 In the ribbon bar, in the Constraints panel, click the Fixed Constraintcommand. The docked dialog box displays.

2 Select the face as shown.


3 Click OK.

The model is now constrained by that face. The browser constraints folder ispopulated with a node representing the constraint.


Add Constraints | 5

Preview Mesh

Before starting the simulation, we can view the mesh.

1 In the ribbon bar, Prepare panel, click Mesh View.

The command is a toggle between model view and mesh view.

2 To return to the model, click Mesh View again.



Run SimulationNow, to run the simulation.

1 In the Solve panel, click the Simulate command to display the Simulatedialog box.

2 Check the More section of the dialog box for messages. Click Run todisplay the simulation progress. Wait for the simulation to finish.


View the ResultsAfter the simulation finishes, the Results folder populates with the variousresults types. The graphics region displays the first mode shaded plot.

In the browser under the Results node and then the Modal Frequencynode, notice the first mode shape (F1) has a check mark by it, indicating it isbeing displayed. There are nodes for the mode shapes corresponding to eachnatural frequency. The color chart shows relative displacement values. Theunits are not applicable since the mode shapes values are relative. (They haveno actual physical value at this point.)

Now you can perform post-processing tasks using the Display commandslocated on the ribbon bar. The commands are described in Help.

Run Simulation | 7

For post-processing of structural frequency simulation studies, the browserlist shows the natural frequencies. Double-click any of these nodes to showthe corresponding Mode Shape 3D plot.

1 Animate the results using the Animate Results command in the Resultpanel on the ribbon bar.

2 While the animation is playing, click Orbit in the navigation tools onthe side of the graphics window. As you orbit the graphics, the animationcontinues to play.

NOTE The following image depicts a frame from the animation of modeF3.


3 Click OK.

4 In the Results browser list of natural frequencies, double-click the resultsfor mode F3 to display that mode.

View the Results | 9


NOTE If you plan to complete the second part of this tutorial, keep this model fileopen. Otherwise, save your model file to a different name before you close it.


Summary

In this first tutorial for Part Stress Analysis, you learned how to:■ Create a simulation for modal analysis.

■ Override the model material with a different material.

■ Specify constraints.

■ Run the simulation.

■ View and interpret the results.

What Next? Continue with “Simulation 2 - Parametric Static Analysis”


Summary | 11

Simulation 2: About this tutorial


Parametric static analysis.

Level 3 special interestSkill Level


PivotBracket.iptTutorial FilesUsed

The second simulation is a parametric study on the same model. Parametricstudies vary the parameters of the model to update geometry and evaluatevarious configurations of a design. In this structural static analysis, the goalis to minimize the weight of the model.

Objectives■ Copy a simulation.

■ Use analysis parameters to evaluate how to refine the weight of the model.

■ Generate configurations of the parametric dimension geometry.

■ Modify design constraints and view results based on those changes.

Prerequisites■ Completed Simulation 1 (Modal Analysis), the first part of this tutorial set.


Navigation Tips■ Use Show in the upper-left corner to display the table of contents for this

tutorial with navigation links to each page.

■ Use Forward in the upper-right corner to advance to the next page.


Copy SimulationWe will create a copy of the first simulation, and edit it to define the secondanalysis.

1 In the browser, right-click the Simulation (Modal Analysis) nodeand click Copy Simulation. A copy of this simulation is added to thebrowser and becomes the active simulation.

Copy Simulation | 13

We will edit the simulation properties to define a parametric dimensionstudy.

2 Right-click the newly created Simulation node, and click EditSimulation Properties.

3 Change the name to Parametric.

4 Change the Design Objective to Parametric Dimension using thedrop-down list.

5 Set the simulation type to Static Analysis.

6 Click OK.


Create Parametric GeometryWe will produce a range of geometric configurations involving the thicknessof the model to facilitate weight optimization. Adding parameters to theparametric table is required.

Add parameters to the parametric table

1 In the Manage panel, click Parametric Table.

2 In the browser, right-click the part node just below the Simulation(Parametric) node, and click Show Parameters.

3 In the Select Parameters dialog box, check the box to the left of theparameter named d2, 12 mm.

4 Click OK.

After identifying the parameter we want to use, we must define a range forthe parameter and generate the corresponding geometric configurations.

Define parameter range

1 In the Values cell for Extrusion1 d2, enter the range 6-12. The valuesmust be in ascending order.

2 Press Enter to accept the values. When you click inside the Value field,the value now says 6-12:3. This indicates that there are now three valuesin the range. These are equally divided between the first and last number,hence that values are 6, 9, and 12.


NOTE The number after the colon specifies the additional configurationsdesired, excluding the base configuration. The base is 12 mm, and the twoadditional configurations are 6 mm and 9 mm.

Once the parameter range is specified, we can generate the variousconfigurations based on the range values.

Generate configurations

1 Right-click the table parameter row, and select Generate AllConfigurations. The model generation process is started.

2 After the model regeneration is completed, move the slider to see thedifferent shapes created.

Create Parametric Geometry | 15

We are not finished with the Parametric Table yet, so do not close it.


Include Optimization CriteriaRemember that our goal for this simulation is to minimize weight. We optimizethe simulation using a range of geometric configurations generated previouslywhile utilizing the Yield Strength failure criteria.

Add Design Constraints

1 In the Design Constraints section, pause the cursor over the emptyrow, right-click, and click Add Design Constraint.

2 In the Select Design Constraint dialog box, click Mass, and click OK.

3 Repeat step 1.

4 In the Select Design Constraint dialog box, Select Von Mises Stress.Ensure that Geometry Selections is All Geometry.

5 Click OK.

Enter Limit values and safety factor

1 In the Von Mises Stress row, click in the Constraint type cell, andselect Upper Limit from the drop-down list.

2 Enter 20 for Limit.

3 Enter 1.5 for Safety Factor .


Add LoadsNext, add the structural load.

1 Click the Force Load command. The dialog box displays.

2 Select the face as shown.


3 Enter 200 N for the Magnitude.

4 Click OK.


Set ConvergenceThe software performs an automatic H-P refinement for parts. In this case, wewant to add an additional H refinement iteration. H refinement increases thenumber of mesh elements in areas where the results need improvement. TheP refinement increases the polynomial degree of the selected elements in thehigh stress areas to improve the accuracy of the results.

1 In the Prepare panel, click Convergence Settings.

2 For Maximum Number of h Refinements, enter 1.

3 Click OK.


Set Convergence | 17

Run SimulationNow we will run the simulation. To start the Simulation, use the Simulatecommand in the ribbon bar or through the simulation node context menu.

1 Click the Simulate command to display the Simulate dialog box.

2 Click Run. The Simulation progress displays. Wait for the simulationto finish.

When the simulation is complete, the Von Mises Stress plot displays bydefault.

3 In the Display panel, click Adjust Displacement Display ,drop-down list, and select Actual.



View the ResultsAfter the simulation finishes, the graphics region displays a 3D color plot, andyou can see that the Result folder is populated. Now we can evaluate theresults through the parametric table and the 3D and XY plots available forpost processing.

Optimize model

First, we optimize the mass using the parametric table populated in previoussteps. Then we look at 3D and XY plots to understand the behavior of themodel under the defined boundary conditions.

The goal is to minimize the mass of the model taking into account parametricdimensions and stress constraints.

1 If you previously closed the Parametric table, reopen it by clicking theParametric Table command.

2 For the Mass Design Constraint, click in the Constraint Type cell,and select Minimize from the drop-down list.

The parametric values change to show the configuration with the least massthat meets the given constraints. In this case, the original thickness value was12 mm and the optimized value is 9 mm which in turn reduces the mass ofthe model.

Note the design constraint Result Value for Max Von Mises Stress. Thevalue has a green circle preceding it. It indicates that the design constraintvalue is within the safety factor range.

Slide the Extrusion1 parameter value to 6. When the table updates, you willsee that the design constraint Result Value is now outside the safety factor.The value is preceded by a red square indicating the design constraint valuehas been exceeded the safety factor. Slide the parameter value back to 9.

View and animate 3D plots

Now you can perform post-processing tasks using the Display panel commandsfor smooth shading, contour plots, etc. These commands are described inHelp.

1 In the Result panel, click Animate Results.

2 In the Animate dialog box, click the Play command. The VonMises Stress plot colors change to reflect the application of the load. To


view the deformation changes, stop the animation, select Adjusted x1

from the Adjust Displacement Display , drop-down list andrestart the animation.

For post-processing of results, double-click the result in the browser to displaythe result in the graphics region. Then, select the Display command you wantto use.

View XY graphs

XY Charts show a result component over the range of a parameter.

To view an XY plot, right-click over the parameter row in the Parametric Tableand choose XY Plot.

In this case, the above XY plot displays Stress results versus parametricconfigurations.



Summary

In this last tutorial for Part Stress Analysis, you learned how to:■ Copy a simulation.

■ Modify the simulation properties to change the type of simulation.

■ Generate configurations of the parametric dimension geometry.

■ Use analysis parameters to evaluate how to refine the weight of the model.

■ Modify design constraints and view results based on those changes.

What Next? As a next step, consider doing the Assembly FEA tutorials. Ifyou have already completed them, why not acquaint yourself with theDynamic Simulation tutorials?

Experiment with what you have seen and used. Explore how you can use thisdesign tool to help you complete your digital prototype with confidence inits performance.

Previous (page 19)

Summary | 21

22

Assembly Stress Analysis

About this tutorial

Simulate the structural static behavior of an assembly for analysis.

SimulationCategory


2

23

analyze-2.iamTutorial File Used

NOTE Click and read the required Tutorial Files Installation Instructions atht-tp://www.autodesk.com/inventor-tutorial-data-sets . Then download the tutorialdata sets and the required Tutorial Files Installation Instructions, and install thedatasets as instructed.

The stress analysis environment is a special environment within assembly,part, sheet metal, and weldment documents. The environment has commandsunique to its purpose.

We analyze a subset of an assembly using the “exclude from simulation”functionality in Stress Analysis. Contact types are changed as required by thephysical behavior of the model. Meshing settings are adjusted to capture thegeometry of the model more accurately.

Objectives■ Create a simulation.

■ Evaluate and assign materials as needed.

■ Add loads and constraints.

■ Identify contact conditions.

■ Create a mesh.

■ Run a simulation.


Prerequisites■ Know how to use the Quick Access toolbar, tabs and panels on the ribbon,

model browser, and context menus.

■ Know how to navigate the model space with the various view tools.

■ Know how to specify and edit project files.


Navigation Tips■ Use Next or Previous at the bottom-left to advance to the next page or

return to the previous one.

Next (page 25)

24 | Chapter 2 Assembly Stress Analysis

http://www.autodesk.com/inventor-tutorial-data-sets


Get StartedTo begin with, we will open the assembly to analyze. With Autodesk Inventorup and running, but with no model open, do the following:

1 Click the Open command on the Quick Access toolbar.

2 Set the Project File to Tutorial_Files.ipj

3 Select Assembly FEA 1 ➤ analyze-2.iam.

4 Click Open.

5 Save the file with a different name, such as: analyze-2_tutorial.iam


Stress Analysis EnvironmentWe are ready to enter the stress analysis environment.

1 On the ribbon, click Environments tab ➤ Begin panel ➤ Stress

Analysis .

2 On the Manage panel, click the Create Simulation command.The Create New Simulation dialog box displays.

The settings provide opportunity to tailor the simulation by specifyinga unique name, single point or parametric dimension design objective,and other parameters.

NOTE On the Model State tab, you specify the Design View,Positional, and Level of Detail to use for the simulation. The settingscan be different for each simulation.

3 Click OK to accept the default settings for this simulation.

The browser populates with a hierarchical structure of the assembly andanalysis-related folders.

Most of the commands in the ribbon panels are now enabled for use. Disabledcommands enable as their use criteria is satisfied.

Get Started | 25


Excluding ComponentsYou can exclude components that are not affected by the simulation or whosefunction is simulated by constraints or forces.

We will exclude the following parts from this simulation:■ Handle

■ Screw

■ SHCS_10-32x6

To exclude these components:

1 Expand the analyze-2_tutorial.iam browser node.

2 Right-click Handle, and click Exclude From Simulation.

3 Repeat the command for both the Screw and SHCS_10-32x6components.

The default display setting for excluded components is partially transparentas seen in the following image:



Assign MaterialsThe next step is to look at the component materials and make adjustments.

For this simulation, we will make a minor material change using materialsthat are fully defined.

Before you begin doing simulations, we recommend that you ensure yourmaterial definitions are complete for those materials being analyzed. When

a material is not completely defined, the material list displays a symbolnext to the material name. If you try to use the material, you receive a warningmessage.

If you attempt to edit a material during this tutorial, you may not be able toif the project setting Use Styles Library is set to No. To edit this setting,you cannot be working in the model. To change the setting requires exiting

Assign Materials | 27

the tutorial. For purposes of this tutorial, use a material that is already fullydefined. You can modify the other materials at a later time.

1 In the Material panel, click the Assign command. The dialogbox displays the list of components, their material assignments, anoverride material, and a column showing how the material safety factoris defined.

2 In the Override Material column, click the first component(Upper_Plate:1) cell to expose the material list.

3 In the list, click Steel.

4 Repeat the process for the all instances of the Upper and Lower plates.Notice that when a components material is changed, all instances ofthat component inherit the change.

5 Click OK to exit the Assign Materials dialog box.

The browser Material folder receives a Steel folder added with all thecomponents referencing that material listed within that folder. If you deleteindividual components from the folder, their material reverts to the assemblyassigned material.


Add Constraints and LoadsNext we define the boundary conditions by adding structural constraints andloads. We start with constraints first.

1 In the Constraints panel, click Fixed . The dialog box displayswith the Location selector active.

2 Select the two holes through which the screw passed. They are the holesthat are left after excluding the screw from the simulation.


3 Click OK. The two faces are axially constrained, as if the screw werethere.

Add Constraints and Loads | 29

Now, we assign loads on the components.

1 In the Loads panel, click Force . The dialog box displays withthe Location selector active.

2 Select the face on the ch_09-Upper_Grip component as shown.

3 In the dialog box, enter 100 for the Magnitude value, and click OK.

4 Repeat the previous steps for the ch_09-Lower_Grip component.


5 Click OK to exit the Force dialog box.


Stress Analysis SettingsStress Analysis settings apply to all new simulations. It is where you definethe default settings that you saw in the Simulation Properties at the beginningof this process.

Stress Analysis Settings | 31

In the Settings dialog box, you can specify:■ Simulation Type

■ Design Objective

■ Contact Defaults

■ Excluded Component Display

■ Other parameters

Though we will not change the defaults for this tutorial, it is good to familiarizeyourself with these settings. You can modify them for your future needs.


Contact ConditionsYou can specify contact conditions either automatically or manually.Automatic contacts are generated according to the tolerance and contact typespecified in the Stress Analysis Settings. You can assign other contact typessuch as Separation, Sliding / No Separation, and so on.

For this simulation, we automatically compute inferred contacts and thenchange some of those to another type.

1 In the Contacts panel, click Automatic . It detects the contactswithin the default tolerance and populates the Contacts folder.

2 Expand the Contacts folder. You can see that all contacts were createdas Bonded contacts (default setting) and placed in a folder. Expand theBonded folder.

3 We must change the contacts listed in the following list. To makechanges, use multi-select. Select one contact, hold down the Ctrl key,and multi-select the remaining contacts in this list.■ Bonded:1 (Upper Plate:1, Lower Plate:1)

■ Bonded:6 (Upper Plate:1, Pin A:3)


■ Bonded:10 (Upper Plate:1, Pivot Threaded:1)


■ Bonded:12 (Upper Plate:2, Lower Plate:2)






■ Bonded:26 (Lower Plate:1, Pivot Lower:1)



■ Bonded:32 Lower Plate:2, Pivot Lower:1)

4 Right-click a selected contact, and click Edit Contact.

5 Change the type to Sliding / No Separation, and click OK.


Generate MeshesBefore running the simulation, view the mesh to make sure that any areasneeding a different mesh setting from the default are cared for. First, we willspecify the mesh settings.

1 In the Prepare panel, click Mesh Settings . Alternatively,right-click the Mesh folder and click Mesh Settings.

2 Set Maximum Turn Angle = 30 to capture round areas of thegeometry.

3 Check Create Curved Mesh Elements.

4 If not already checked, check Use part based measure for assemblymesh.

This option uses the part size as mesh criteria, as opposed to a single sizefor all parts.

5 Click OK.

6 Having specified the mesh settings, you preview the mesh by clicking

the Mesh View command. The results are a mesh overlay onevery part participating in the simulation.

Generate Meshes | 33

NOTE If areas of the model need a finer or more coarse mesh, add local meshcontrols. Local mesh controls are covered in another tutorial.


Run the SimulationWe are now ready to run the simulation.

1 In the Solve panel, click Simulate . The Simulate dialog boxdisplays.

The dialog box more command >> exposes the messages section. If thereare process steps to do, such as add constraints, the message is reportedhere.

2 Click Run. The simulation processes and returns results.



View and Interpret the Results

After the simulation completes, the graphics display presents the Von MisesStress results plot. The complete set of results is posted in the Results folder.

There are various commands for viewing result data. Most are located in theResult and Display panels.

1 In the Display panel, click Show Maximum Value . In thegraphics window, a label with a leader points to the location of themaximum value. In this example, the maximum value is obscured byother components.

2 Expand the assembly browser node to view the list of components.

3 Turn off visibility of the parts hiding the stress location.■ Lower Plate:1

■ Upper Plate:1

Right-click each component, and click Visibility.

4 Rotate and Zoom as needed to view the location of the MaximumValue.

View and Interpret the Results | 35

Double-click the various results nodes to display the results in thegraphics window.



Summary

The previous image is what you see if you look at the Displacement resultsfor this simulation.

Now that you have completed this tutorial, you have a basic understandingof the typical workflow in the stress analysis environment. This workflowincludes:■ Creating a simulation.

■ Excluding components not needed for the simulation.

■ Assigning materials as overrides of the existing material.

Summary | 37

■ Adding constraints and loads, sometimes called boundary conditions.

■ Adding contact conditions.

■ Generating meshes.

■ Running the simulation.

■ Viewing and interpreting the results.

What Next? As a next step, look into creating advanced contact conditionsand local mesh controls. The Contacts and Mesh Refinement tutorialtakes you into these topics.

Previous (page 35)


Contacts and Mesh Re-finement

About this tutorial

Use advanced and local mesh refinement to improve the stress results.

SimulationCategory

3

39


Bracket_Assembly.iamTutorial File Used


Two simulations are covered. The first one corresponds to a structural staticstudy with separation contact and advanced meshing settings. The secondone involves additional local mesh control.

Objectives■ Apply manual contacts.

■ Modify automatic contacts.

■ Add local mesh controls.

Prerequisites■ Be familiar with the Stress Analysis environment, and complete the tutorial

Assembly Stress Analysis.

■ Know how to use the model browser and set the active project.




Next (page 40)

Open the ModelThe first simulation walks, step by step, through the definition of a structuralstatic FEA analysis. It includes the creation of manual contacts and selectionof advanced meshing settings and concludes by viewing the results.

1 Check to see that project file is set to Tutorial_Files.ipj.

40 | Chapter 3 Contacts and Mesh Refinement



2 On the ribbon, click Get Started tab ➤ Launch panel ➤ Open .

3 Navigate to the Assembly FEA 2 folder, and then clickBracket_Assembly.iam.

4 Click Open.


Stress Analysis EnvironmentSwitch to the Stress Analysis environment.

1 Click the Environments tab.

2 Click the Stress Analysis environment command.


Create a SimulationCreate a simulation.

1 Click Create Simulation , to display the Create New Simulationdialog box.

2 For the simulation Name, enter Separation Contact.

3 On the Simulation Type tab, specify Static Analysis.

4 Click OK. A new simulation named Separation Contact is createdand appears in the browser.


Stress Analysis Environment | 41

Exclude ComponentsFor this simulation, the Sleeve component is not relevant, so we will excludeit.

1 In the browser, expand the model node to reveal the components of theassembly.

2 We want to evaluate the response to forces of the bolt when the Sleevecomponent is not present. We must exclude it from the simulation.Right-click the Sleeve component and select the Exclude FromSimulation option. Alternatively, right-click the Sleeve component inthe graphics region, and click the command.


Assign MaterialsThe next step is to define the Materials. When a simulation is created, aMaterial folder is included in the simulation structure. This Material folderis populated whenever you specify override materials in place of the originallyassigned material.

1 Double-click the Material folder. In the Assign Materials dialog box, aspreadsheet-type list containing all the parts and their materials displays.


2 In the Override Material column, click the cell corresponding withthe Bolt component.

3 In the drop-down list, select Steel.

4 Right-click the cell, and click Copy.

5 For the following parts, multi-select the cells in the Override Materialcolumn, right-click, and click Paste.■ Bracket

■ Mount

■ Washer

■ Nut

NOTE All occurrences of the Washer are updated at one time.

6 Click OK.


Add Constraints and LoadsTo define constraints and loads, use the commands available in the ribbonpanels. Alternatively, right-click the browser node for the input type, and clickthe command there.

1 On the ribbon, click Stress Analysis tab ➤ Constraints panel

➤ Fixed.

The dialog box displays with the Face selector active.

2 Choose the appropriate faces. Multiple faces can be selected. In this case,the faces represent a rigid attachment that occurs later in themanufacturing process.


3 Click OK to complete the constraint inputs.

Add the second constraint:

1 Click the Fixed command.

2 Select the cylindrical faces of the slot feature.


3 Click OK.

Next, we add a force or load. These steps define a condition where the assemblyreceives a constant load in a given direction.

1 Click Stress Analysis tab ➤ Loads panel ➤ Force.

The dialog box displays.

2 Choose the flat face at the bolt head.

3 Click the More command to expand the dialog box, and check UseVector Components.

4 For the Fz component, enter 225. It defines the force magnitude anddirection.


5 Click OK.

We now have defined materials, structural load, and constraints. In thebrowser, expand the Constraints and Loads nodes for viewing. Click a nodeto highlight the selection or location in the graphics window; and double-clickto edit the definition.


Define Contact ConditionsYou define contacts manually by selecting pairs of faces; these contacts areuseful for cases in which the initial default contact tolerance is too small.Before manually adding contacts, use Automatic Contacts to detect thein-tolerance contact conditions.

1 In the Contacts panel, click Automatic . Contact conditionsare automatically defined using the Contact defaults from the StressAnalysis Settings.


As you manually add contacts, you choose from various contact types suchas Separation, Sliding / No Separation, and so on.

We will now define manual contacts and set them to the Separation type.Additionally, we will modify two automatically created contacts to be theSeparation type.

1 Click the Manual command.

2 Set the Contact Type to Separation.

3 Select the faces for the new contacts as follows

a

In the graphics region, click the Bolt cylindrical face as selection1.

Define Contact Conditions | 47

b

Move the cursor over the area where the Bolt component passesthrough the Bracket. When the cylindrical face on the Brackethighlights, click to select it.

c Click Apply.

d Reorient the model to do the same for the similar area near theBolt head.

e

Click the cylindrical face of the Bolt component.


f

Move the cursor over the area where the Bolt component passesthrough the Bracket. When the cylindrical face on the Brackethighlights, click to select it.

g Click OK.

Now, we modify two automatic contacts to change them to the Separationcontact type.

1 In the browser, expand the Contacts and then the Bonded folders.

2 Select contact Bonded:1, then hold down the Ctrl key and selectcontact Bonded:2.

3 Over one of the selected contacts, right-click and select Edit Contact.

4 Select Separation from the Contact Type drop-down list. It assignsthe selected contact condition.

5 Click OK.

With the contact conditions defined, we can move to specifying the meshsettings.


Define Contact Conditions | 49

Specify and Preview Meshes

1 In the Prepare panel, click Mesh Settings . The settings dialogbox displays.

2 Toward the bottom of the Common Settings section, click the checkbox for Create Curved Mesh Elements.

3 If Use part based measure for Assembly mesh is unchecked, checkthe option.

This option is useful when you need a higher mesh resolution in smallerparts. It generally leads to larger number of elements for the overallassembly.

4 Click OK.


Before starting the simulation, we can view the mesh. In the Prepare panel,

click Mesh View . Alternatively, in the browser, right-click the Meshfolder to access the command.


Run the SimulationNow, we will run the simulation.

1 In the Solve panel, click the Simulate command. The Simulatedialog box displays.

If there are any preprocess related messages, they are presented in theexpanded section of the dialog box. Click the More command (>>) toexpand the dialog box.

2 When ready, click Run, the Simulation progress displays in the dialogbox. Wait for the simulation to finish.

You can run more than one simulation at a time. Multi-select the simulationnodes in the browser, right-click, and click Simulate. The results are displayedwithin the Results folder of each simulation.


View and Interpret the ResultsAfter the simulation finishes, the Results folder is populated with thesimulation results and the graphics region updates to display a results plot.

1 Expand the Results folder. By default, the Von Mises Stress plotdisplays.

Run the Simulation | 51

2 In the browser, the current result plot has a check mark by the nodeicon. To activate other plots, double-click the particular plot node youare interested in seeing. The display updates to present that plot.

Now you can perform post-processing tasks. For example, viewing the resultswith smooth shading or contour plots.

1 In the Display panel, click Show Maximum Value .


2 Using the view commands, reorient the model so you can see themaximum value area.

3 If the maximum value location is obscured by other components, youcan hide those components. In the browser, right-click the componentsand click Visibility.

Maximum values can be also shown in the Parametric Table for summary andcomparison with other simulations. In this case, we will add a DesignConstraint, maximum result value, for the assembly.

1 In the Manage panel, click Parametric Table .

2 In a table cell, right-click and click Add Design Constraint. The SelectDesign Constraint dialog box displays.

3 Click Von Mises Stress.

4 Click OK.


We have concluded the first simulation. The second simulation uses most ofthe items defined in this first simulation. The simulation study will beduplicated and modified as required for the additional study.


Copy and Modify SimulationThe second simulation uses the same analysis as the first simulation. Inaddition, a local mesh refinement is defined to improve the stress results.

We will create a copy of the first Simulation Study and edit the copy to definethe second analysis.

1 Right-click the Simulation Study (Separation Contact) node at thetop of the browser and click Copy Simulation. The new simulation isautomatically activated.

2 Right-click the newly created Simulation Study browser node and clickthe Edit Simulation Properties. The properties dialog box displays.

3 Change the simulation Name to Local mesh refinement.

4 Click OK.


Specify Local Mesh ControlsNext, we define the local mesh refinement.

1 Activate Mesh View and orient the model as shown.

2 Right-click the Mesh folder, and click Local Mesh Control.

3 Select the corner blend face, and enter 0.5 mm for the Element Sizevalue.


4 Click OK.

5 To preview the mesh, right-click the Mesh folder and click UpdateMesh.

Specify Local Mesh Controls | 55

The mesh preview shows a much finer mesh at the corner blend face comparedto the mesh from the first simulation.


Run the Simulation AgainAfter making the previous modifications, run the Simulate command usingthe right-click menu or the command from the ribbon.

1 In the Solve panel, click the Simulate command, the Simulatedialog box displays.


2 Click Run. The Simulation progress is reported in the dialog box.

3 Click OK.


View and Interpret the Results AgainAgain, the Results folder is populated with the results.

1 Expand the Results node. By default, the Von Mises Stress plot displays.

2 In the Display panel, click Show Maximum Result to displaythe location of the maximum result. Hide components, as needed, tosee the exact location.

View and Interpret the Results Again | 57

Maximum result values can be also shown in the Parametric Table for summaryand comparison with other simulations. In this case, we will add a localconstraint (maximum result value for a specific assembly component)

1 In the Manage panel, click the Parametric Table command.

2 Right-click on a cell in the table, and click Add Design Constraint.

3 Click Von Mises Stress

4 Close the parametric table.

To compare result values in the Parametric table, simply check thecorresponding boxes in the other simulation studies.



Summary

In this tutorial, you created two simulations. In completing each simulation,you learned how to:■ Copy an existing simulation to make new ones.

■ Define manual Contacts.

■ Modify automatic contacts.

■ Add local mesh controls.

■ Display design constraints in the parametric table.

■ Use multi-select to change component visibility.

■ Use Copy / Paste for material overrides.

What Next? As a next step, consider completing the following tutorials:■ Part Modal and Stress Analysis

■ Assembly Modal Analysis

Previous (page 57)

Summary | 59

60

Assembly Modal Analysis 4

61

About this tutorial

Perform a structural frequency (modal analysis) study to find natural modeshapes and frequencies of vibration.

SimulationCategory


Suspension-Fork_Complete.iamTutorial FilesUsed

62 | Chapter 4 Assembly Modal Analysis


The tutorial uses an Inventor assembly. It demonstrates the process to create,solve and view results using 3D plots to illustrate the various mode shapesand corresponding frequency values.

Manual contacts and selection of advanced meshing settings are included.The first 10 mode shapes are found and the results are explained.

Objectives■ Create a new modal simulation.

■ Use Manual Contacts to establish the correct relationship betweencomponents.

■ Exclude components, or use a Design View Representation to removecomponents from the simulation.

■ Override materials.

■ Add constraints.

■ Manually add contacts.

■ Specify mesh parameters.

■ Run the simulation.

■ View the results.

Prerequisites■ Complete the Assembly Stress Analysis & Contacts and Mesh

Refinement tutorials.




Next (page 64)

About this tutorial | 63



Open the Assembly

1 Check to see that the project file is set to Tutorial_Files.ipj.

2 Click the Open command, and navigate to the Assembly FEA 3 folder.

3 Click on Suspension-Fork_Complete.iam, and click Open.Alternatively, double-click the .iam file.

4 Use Save As to save the model to a new name, such asSuspension-Fork_Stress.iam. It is not necessary to say Yes to allcomponents.

5 In the model browser, expand the Representations folder and thenthe Level of Detail folder.

6 Double-click the All Parts Suppressed level of detail representation.


7 In the browser, right-click and clear the check mark next to Suppressfor the following components:■ Fork-Crown:1

■ Fork-Slider:1

■ Fork-Tube:1

■ Fork-Slider_MIR:1

■ Fork-Tube_MIR:1

8 Right-click the Level of Detail folder node, and click New Level ofDetail.

9 Rename the new representation to Stress LOD.

10 Save the assembly model.

We made this level of detail representation to take advantage of the stressanalysis environments use of representations.


Create a Simulation StudyTo create a simulation you must switch to the Stress Analysis Environment,then you can begin to define the simulation.


Analysis.

This action takes you into the stress analysis environment.

2 Click on the Create Simulation command. The Create NewSimulation dialog box displays.

3 For the Simulation Name, specify Mode Shapes.

4 Leave the Design Objective set to Single Point.

5 For Simulation Type, select Modal Analysis.

6 Enter 10 for the number of modes.

7 Check the Enhanced Accuracy option. The remaining parameters usedefault settings.

Create a Simulation Study | 65

8 On the Model State tab, for Level of Detail, select Stress LOD. Notethat it may already be active.

9 Click OK. A new Simulation Study is created and populates the browserwith simulation-related folders.


Exclude ComponentsIn any assembly, there can be components and part features that are notaffected by the forces acting on the assembly or have no bearing on theoutcome of applying the forces.

For these reasons, and to help the simulation solve faster, it is good to excludethose parts when simulating an assembly response. For a single part simulation,you consider suppressing specific model features.

For an assembly analysis, you use the component context menu optionExclude From Simulation. Exclusion is different from suppression, whichis what is done when you use a Level of Detail representation. If you thinkyou plan to use the component at a later date in the same simulation, thenuse the Exclude From Simulation. If you know you will not refer to itlater, then you can use a Level of Detail representation.

Because we purposely defined an Assembly Level of Detail representation forthis stress analysis simulation, we do not need to exclude several parts. Wesimply specify that the simulation will use that representation.

NOTE In most cases, this is the optimum way to lower the component count.

If you do not specify the Level of detail representation when first creating thesimulation, then you can use the following steps to make use of it.

1 Right-click the Simulation browser node, and click Edit SimulationProperties.

2 Click the dialog box Model State tab.

3 For Level of Detail input, click the drop-down list and select StressLOD.

4 Click OK. The assembly updates to represent the requested level of detail.

This workflow illustrates how advanced planning, wherever possible, canreduce the effort needed in other phases of your design project.



Assign MaterialsNext, you define the component materials. Not all Autodesk Inventor materialsare suited to analysis, so it is necessary to define materials completely inadvance, or select from the materials that are defined.

If you want to modify materials, use the Materials and Appearances tools.Modifying materials is not part of this tutorial.

1 On the ribbon, click Stress Analysis tab ➤ Material panel ➤ Assign

.

The dialog box displays.

2 In the Override Materials column, click the cell for the firstcomponent. It activates the materials list within the cell.

3 Click the down arrow to display the drop-down list, and click Titanium.

4 Right-click the cell, and select Copy.

5 Multi-select the other component cells of the Override Materialcolumn, right-click, and select Paste.

6 Click OK to accept the changes and close the dialog box.

The Material browser node is populated with a material node containinga node for each component assigned that material override.


Add ConstraintsUsing constraints, we specify the boundary conditions for this simulation.

1 In the Constraints panel, click Fixed Constraint. The dialog boxdisplays with the Selector command active and ready for use.

2 Choose the Fork-Crown face as shown in the following image.


3 Click OK.


Create Manual ContactsTo define contacts, we must do two things. First, we must have the softwareautomatically detect contacts that meet the default criteria found in the StressAnalysis Settings. Second, we must manually define additional contacts.

Manual contacts, consisting of pairs of faces, are used for cases in which theinitial default contact tolerance is too small.

The default contact type is bonded; however, you can also assign variouscontact types such as Separation, Sliding/no Separation, and so on.

In this example, we add a manual bonded contact to model the relativedisplacement of the fork elements.

1 In the Contacts panel, click Manual Contacts.


Since you have not already run an automatic detection of contacts, youwill receive a message that automatic detection will be run before manualcontacts can be added.

2 Click OK.

Automatic contacts detect contacts within the default tolerance. Qualifiedcontacts populate the Contacts folder. Once automatic contacts havebeen established, the Manual Contacts dialog box displays.

To see the automatically created contacts, expand the Contacts folderin the browser.

3 When the Manual Contacts dialog box appears, select the outer surfaceof Fork-Tube.ipt and the main interior surface of the Fork-Slider.iptcomponents. The contact type should be Bonded. Click Apply.

4 Check to see if a contact was made between the Fork-Tube_MIR.iptand the main interior surface of the Fork-Slider_MIR.ipt components.The contact type should be Bonded. If not, create the contact with thesecomponents using the method from step 3.

5 One more manual contact must be added to represent the componentto which the Fork-Sliders are bolted. Select the two opposing faces of theFork-Slider as shown in the following image. View navigation commandsare available to orient the view.

6 Ensure the contact type is Bonded.

7 Click OK. A bonded contact is assigned between the two faces as seenin the image.

Next, we specify the meshing options.


Create Manual Contacts | 69

Specify Mesh OptionsUse the advanced meshing settings to create a mesh that considers this typeof curved and long geometry.

1 In the Prepare panel, click Mesh Settings.

2 In the dialog box:■ Set Average Element Size to 0.05.

■ Check Create Curved Mesh Elements. Use this option to bettermesh round areas of the geometry.

■ Ensure that Use part based measure for assembly mesh ischecked. This option creates a higher mesh resolution in smallerparts; it usually generates more elements for the overall assembly.

3 Click OK.


Preview Mesh and Run SimulationBefore starting the simulation, we can view the mesh.

1 In the Prepare panel, click Mesh View. Alternatively, you canright-click the Mesh browser folder and select the command.

The command is a display state command and acts like an on/off switchfor the mesh display. Notice that in the upper corner of the graphicswindow the node and element counts are presented.


2 In the Solve panel, click the Simulate command and a dialog boxdisplays.

3 Click Run, the Simulation progress displays in the dialog box.


View and Interpret ResultsAfter the simulation finishes, the graphics window displays the first mode,and the Results browser folder populates with all the simulation results.

View and Interpret Results | 71

1 Expand the Results folder.

2 Expand the Modal Frequency folder to expose the list of availableMode Shapes corresponding to each calculated natural frequency.Double-click the frequency of choice to display it.

The color bar shows relative displacement values. The units are notapplicable since the mode shapes values are relative (They have no actualphysical value at this point)

Now you can perform post-processing tasks using the Display panelcommands. These commands are described in Help.

Animate the results

1 In the browser, select a mode shape you want like to see animated.

2 Click the Animate Results command on the Result panel.

3 Specify 10 for the number of steps. Steps are analogous to images forplayback.

4 In the dialog box, click the Play command.


5 When finished observing the displacement animation, click OK to exitthe animation playback.

The Animate Results dialog box also has options for displaying the originalwireframe with the plot. You can also record the animation to present or retainfor records.


Summary

In this tutorial you performed a structural frequency (modal analysis) analysiswith the goal of finding natural mode shapes and frequencies of vibration.The steps performed included:■ Create a modal simulation.

■ Use Manual Contacts to establish the correct relationship betweencomponents.

■ Exclude components, or use a Design View Representation to removecomponents from the simulation.

■ Override materials

■ Add constraints

■ Manually add contacts

■ Specify mesh parameters

■ Run the simulation

■ View the results

Summary | 73

What Next? As a next step, visit http://www.autodesk.com and try some ofthe Skill Builders for Stress Analysis. Try using some of these learned techniqueson your models.

Previous (page 71)


http://www.autodesk.com

FEA Assembly Optimiza-tion 5

75

About this tutorial

Optimize an assembly model using the parametric variations provided in StressAnalysis.

SimulationCategory


Robot Base.iamTutorial FilesUsed

76 | Chapter 5 FEA Assembly Optimization


Objectives

Minimize the mass of the structure while keeping displacement and stresswithin allowable values. Consider safety criteria and profile size changes.

Prerequisites■ Complete the Part Modal and Stress Analysis tutorial.

■ Familiarize yourself with the ribbon user interface.



Next (page 77)

Open the Assembly

1 Click ➤ Open.

2 Set the Project File to Tutorial_Files.ipj.

3 Open Assembly Optimization using FEA ➤ Robot Base.iam.


Analysis .


Define the Simulation

1 On the ribbon, Manage panel, click Create Simulation .

Open the Assembly | 77



2 In the Create New Simulation dialog box, enter the following:■ Name: Optimization

■ Design Objective: Parametric Dimension

■ Simulation Type: Static Analysis

3 Click OK. A new simulation is created and the browser is populated withfolders.


Assign Materials

1 On the ribbon bar, Material panel, click Assign Materials .

2 For the base_plate:1 component, click the Override Material drop-downlist and select Steel. Notice that the Safety Factor column shows thatYield Strength is used for safety analysis.

3 Right-click the Override Material cell for base_plate:1 and select Copy.Multi-select the other Override Material cells, right-click, and selectPaste. Multiple instances of a component change with one paste. ClickOK to close the dialog box.


Adding ConstraintsAdd constraints to denote mechanical and environmental conditions.

1 On the ribbon bar, Constraints panel, click Fixed .

2 Rotate the model and select the faces that would contact the floor surface.


3 Click OK.


Adding LoadsDefine the load where the robot mounts to the base. The mounting plate onthe robot is round, and the base plate is square. To apply the force in the areawhere the robot mounts, we must split the base plate face. (This step hasalready been performed for you.)

1 On the ribbon bar, Loads panel, click Force .

2 Move the cursor over the center of the base plate component to highlightthe round face. Click to select the face.

Adding Loads | 79

3 In the Force dialog box, for Magnitude, enter 2000 and click OK. Ayellow (default color) glyph denoting the force direction is positionedat the center of the face.


Modify the MeshReview the mesh settings and make a minor adjustment.

1 On the ribbon bar, Prepare panel, click Mesh Settings .

2 In the Mesh Settings dialog box, click Create Curved Mesh Elements.This option creates elements that follow geometry curvature.

3 The Use part based measure for Assembly mesh option is checked bydefault, which is correct for this simulation. This option produces ahigher mesh resolution in smaller parts, with a resulting increase in meshelements overall.

4 Click OK to apply the change and close the dialog box.



Preview the MeshPreviewing the mesh is an optional step. Perform the mesh preview to examinethe mesh in areas where features are smaller, or where transitions occur, toensure an adequate mesh results.

On the ribbon bar, Prepare panel, click Mesh View .


Preview the Mesh | 81

Create Parametric GeometryProduce a range of geometric configurations, involving the width of the modelcomponents, to facilitate weight optimization. First, expose model parametersfor use as simulation parameters.

1 In the Simulation browser, expand the Robot Base.iam node to exposethe components in the assembly. Right-click base_plate:1 and click ShowParameters.

2 In the Select Parameters dialog box, select the check box next to theMemberWidth parameter to include the parameter in the parametrictable.

3 Click OK.

Define the parameter range.

1 On the ribbon bar, Manage panel, click Parametric Table .

2 In the Parameters section, base_plate.ipt row, for the MemberWidthparameter, enter 1-2 in the Values cell. Press Enter to update the rowcontents.


Once the parameter is defined, generate the parametric configurations.

1 In the Parameters section, right-click the MemberWidth row and selectGenerate All Configurations.

2 After the configurations are generated, you can view them using theCurrent Value slider.

Create Parametric Geometry | 83


Optimization CriteriaAs mentioned at the outset, the goal is to minimize the mass using the rangeof geometric configurations and safety factor criteria. The Design Constraintssection of the Parametric Table enables access to the results criteria. To addthe first design constraint:

1 If the Parametric Table is not displayed, in the Manage panel, clickParametric Table.

2 In the Design Constraints section, right-click the row and select AddDesign Constraint.

3 In the Results Component section of the Select Design Constraint dialogbox, select Von Mises Stress. Geometry Selections is set to All Geometry.Click OK. The result component is listed as a design constraint.

4 In the Max Von Mises Stress row, click the Constraint Type cell to accessthe drop-down list. In the drop-down list select Upper limit.

5 In the Limit cell, enter 4.5e+004.

6 In the Safety Factor cell, enter 1.5.

Add Displacement as a design constraint.

1 Right-click a row and click Add Design Constraint.

2 In the Select Design Constraint dialog box, select Displacement. AllGeometry is the default. Click OK.

3 In the Constraint Type cell, select Upper limit.

4 In the Limit cell, enter 0.01.

Add Mass as a design constraint.

1 Right-click a row and click Add Design Constraint.

2 In the Select Design Constraint dialog box, select Mass and click OK.

For the Mass design constraint, leave the constraint type as View thevalue. The Design Constraints section of the Parametric Table shouldlook like the following image:


Close the table.


Run the Simulation

1 On the ribbon bar, Solve panel, click Simulate .

2 In the Simulate dialog box, ensure that the simulation will run usingthe Smart set of configurations.

3 Click Run.


View and Interpret the ResultsThe Simulation browser Results node is populated with the simulation results.

However, we use the Parametric Table and the visualization capabilities toassess the design and optimize for mass.

1 On the ribbon bar, Manage panel, click Parametric Table.

2 In the Parametric Table, note the presence of a green circle in two ResultValue cells. A green circle indicates that the Result Value is within theassociated safety factors.


3 Change the Mass Constraint Type to Minimize.

The parametric values change to show the configuration with the leastmass that meets the given constraints. In this case, the original profilewidth value was 2 inches. The optimized configuration is 1.5 inches,which reduces the mass.

NOTE If you move the slider to show a current value of 1.0, the table updatesand you see that maximum displacement exceeds the safety factor criteria.A red square, next to the Result Value, denotes the condition.



View and animate 3D plotsView 3D and XY plots to understand the behavior of the model under thedefined boundary conditions.

After running a simulation, you can perform post-processing tasks using theassorted commands in the Display panel. You can choose shading options,display minimum and maximum labels, insert probes, and so on.

The Results node, in the Simulation browser, is populated with the simulationresults based on the criteria you specified. The Von Mises Stress result (default)is displayed as a 3D color plot.

In this example, because of the connections between profile geometry, stressconcentrations are expected at the joints. To see the stress distribution fartheraway from the concentrations, change the Color Bar settings.

1 On the ribbon bar, Display panel, click Color Bar.

2 In the dialog box, uncheck Maximum.

3 Enter 5 in the edit field above the check box. Click Apply.

4 Use the view commands to rotate the model so you can see the undersideof the assembly. Note how the stress is distributed in the members.

View and animate 3D plots | 87

To view other results such as Displacement, double-click the appropriatebrowser node to update the display.

For simulations involving parametric dimensions, move the slider to variousparameter values to display the associated results.


View XY PlotsXY plots show a result component over the range of a parameter. To view anXY plot, right-click the parameter row and select XY Plot.


The XY plot displays the Displacement results versus the parametricconfigurations. Hover the cursor over a plot point to display the displacementvalue at that point.

View XY Plots | 89


SummaryIn this tutorial, you learned to:■ Create a simulation.

■ Specify materials, constraints, and forces.

■ Specify parametric dimensions and generate configurations.

■ View different configurations as 3D color plots and XY plots.

What Next?


If you have not completed the other FEA tutorials, why not do so now? Or,if you have not used Dynamic Simulation, work through those tutorials andlearn how to use that simulation output in the Stress Analysis environment.

Consider how this process applies to the products you design and manufacture.

Previous (page 88)

Summary | 91

92

Stress Analysis Contacts

About this tutorialUse contacts to simulate interactions between assembly components in InventorStress Analysis.

SimulationCategory


Caulk Gun.iamTutorial Files Used

NOTE Click and read the required Tutorial Files Installation Instructions atht-tp://www.autodesk.com/inventor-tutorial-data-sets . Then download the tutorial datasets and the required Tutorial Files Installation Instructions, and install the datasetsas instructed.

Prerequisites

Perform some of the other Stress Analysis tutorials to become familiar with theStress Analysis environment..

Navigation Tips■ Use Next or Previous at the bottom-left to advance to the next page or return

to the previous one.

Next (page 94)

6

93



OverviewIn the structural analysis of an assembly involving multiple parts, you createcontacts to define the relationship between the parts. Contacts transfer loadbetween parts while preventing parts from penetrating each other. Contactscan simulate interaction between bodies that separate or come into contactduring loading. Without contacts, parts do not interact with each other inthe simulation.

There are several different contact types you can use to simulate the physicalbehavior of an assembly. This tutorial presents an assembly modeled withmany of the types of contact available in Inventor Stress Analysis. The contactshave already been created, either automatically or manually, in the model.


Open the AssemblyA model of a caulk gun illustrates different contact types and how to use themin a static, structural analysis.

1 Click ➤ Open.

2 Set the Project File to Tutorial_Files.ipj.

3 Open Stress Analysis Contacts ➤ Caulk Gun.iam.

94 | Chapter 6 Stress Analysis Contacts



How a Caulk Gun WorksWe considered the following mechanics of the caulk gun when creating thesimulation.


How a Caulk Gun Works | 97

1 User holds the handle [1] and pulls back on the trigger [2].

2 The pin end of the trigger [3] pushes the actuator [4] forward.

3 The actuator tightly engages the plunger [5] and pushes it forward.

4 The plunger head [6] pushes the caulk tube bottom.

5 The tube is held in place by a ring [7] at the end of the caulk gun.



Assembly SimulationThe caulk gun is an assembly which consists of several parts, some of whichcan move. Several operational scenarios can exist for the caulk gun, but wechose to simulate the assembly in a static equilibrium state.

This simulation investigates when the trigger is pulled and the pushing forceon the bottom of the caulk tube is about to overcome the internal tuberesistance. At this instant, just before caulk exits the tube, the assembly is instatic equilibrium.

On the ribbon, click Environments tab ➤ Begin panel ➤ Stress

Analysis to enter the Stress Analysis environment.

Expand Caulk Gun.iam in the Stress Analysis browser. We exclude thefollowing components from the simulation:■ Caulk Tube [8]

■ Actuator Spring [9] (not modeled, but simulated with Spring contact)

■ Lock Spring [10]

■ Lock [11]

Assembly Simulation | 99


Contact TypesInventor Stress Analysis provides the following Contact types:■ Bonded

■ Separation

■ Sliding / No Separation

■ Separation / No Sliding

■ Shrink Fit / Sliding

■ Shrink Fit / No Sliding


■ Spring

In the Stress Analysis browser, expand the Contacts node to view the contacttypes currently in use for the caulk gun simulation. As you create or editcontacts, they are added under existing contact type nodes or to newly creatednodes.

Contact Types | 101

In the browser, right-click a contact and select Edit Contact. The EditAutomatic Contact or Edit Manual Contact dialog box displays and shows theavailable contact types:


Bonded ContactThe Bonded contact simulates rigid bonding of faces to each other. TypicalBonded contacts include weld or glue joints between two parts.

In the model, the Front Frame-Main Frame and the Front Frame-Handleinterfaces are weld joints, as shown in the following image. You use Bondedcontacts to simulate these joints in the simulation.



Separation ContactThe Separation contact allows separation between parts but prohibits partpenetration.

In the model, the pin end of the trigger contacts the actuator. When you pullthe trigger, the pin end of the trigger pushes the actuator forward. When thetrigger is released, the pin end and the actuator can separate. Since the pinend cannot penetrate the actuator and separation can occur between the parts,the contact relationship is simulated with the Separation contact.

Separation Contact | 103


Sliding and No Separation ContactThe Sliding/No Separation contact allows relative sliding between contactfaces, but prohibits separation.


Sliding/No Separation can occur between planar faces like the Trigger-Handleinterface.

Sliding and No Separation Contact | 105

It can also occur between circular faces such as the Pin-Handle and Pin-Triggerinterfaces.



Separation and No Sliding ContactThe Separation/No Sliding contact allows contact faces to separate, butprohibits relative sliding when they touch.

For the Actuator-Plunger interface, the Separation/No Sliding contact isappropriate. When the trigger is pulled, the actuator is pushed forward. Thisresults in separation between the top surface of the plunger and the actuator.At the same time, engagement occurs between the bottom surface of theplunger and the actuator. It is reasonable to assume that theengagement/separation occurs without slippage between the actuator andplunger.

In the following image, note that the surfaces of the plunger and actuator aresplit into multiple faces. In this manner, the contact surfaces are more explicitlydefined.

Separation and No Sliding Contact | 107


Shrink Fit and No Sliding ContactThe Shrink Fit/No Sliding contact simulates conditions like Separation/NoSliding with the parts in an initial state of interference.


The model has a ring that tightly fits the front frame and prevents the caulktube from exiting the caulk gun when the plunger moves forward. The frontface of the ring registers against the front frame without penetration. Therefore,this interface is simulated with the Separation contact.

The outer diameter of the ring has an interference fit with the front frame.The ring is press fit into the frame so that it remains in position without acaulk gun in place. This press fit allows the operator to push the ring out easilyand replace it with a different size, as appropriate. The outer diameter of thering and the front frame can separate without sliding. Since they are initiallyin a state of interference, the Shrink Fit/No Sliding contact is appropriate.

Shrink Fit and No Sliding Contact | 109


Spring ContactThe Spring contact simulates conditions of a spring between two faces.

In the model, the actuator spring is simulated using a Spring contact. The useof the Spring contact eliminates complexities associated with modeling thephysical spring part.



Loads and ConstraintsWith the contacts defined, proceed further with the model analysis.

To use the caulk gun, you hold the handle and pull the trigger. From the staticanalysis point of view, the components are under force and deform beforethe plunger head moves the bottom of the tube. We can reasonably assumethat the components deform relative to the main frame. As such, we can applya:■ Fixed constraint on the main frame edge [12]

■ Force on the handle [13]

■ Force on the trigger [14]

■ Force on the plunger head [15]

■ Force on the ring [16]

Loads and Constraints | 111

The tube is held in place by the front frame, ring, and plunger head. Whenthe force from plunger head is large enough, the bottom of the tube movesfurther into the tube and pushes caulk out of the nozzle. For the static analysis,we simulate the instant at which the force on the tube bottom is in equilibriumwith the tube resistance. Before the tube bottom moving, we examine thestress and deformation of the whole structure and components.


Simulation Results

1 On the Stress Analysis tab, Solve panel, click Simulate .

2 On the Simulate dialog box, click Run to begin the simulation.

The Simulate dialog box remains open, displaying the progress bar, until thecomputation is complete.


When the simulation finishes, a deformation plot of the model is shown inthe graphics window. The Von Mises Stress results are also displayed usingthe default color bar settings. On the Display panel, click Maximum Value

to view the maximum stress and its location.

The maximum Von Mises Stress of approximately 291 MPa occurs on the Pin.To view the location of maximum stress, turn off the visibility of all partsexcept the Pin.

Simulation Results | 113

As this stress is greater than the Pin material (steel) yield strength of 207 MPa,the analysis indicates the Pin will yield. To meet strength criteria, you modifythe design or change the Pin material.

NOTE In this tutorial, the model is intended to illustrate the contact types andtheir application. Some contact areas such as the Plunger-Actuator interface aresmall. Take care when providing spring stiffness and force values as thedisplacement and stress results are sensitive to parameter values. Also note thatsome parts may have areas of large deformation, which are better suited to anonlinear analysis.


SummaryIn this tutorial, you learned about Inventor Stress Analysis contacts and howthey simulate interactions between assembly components.

What Next?

To investigate design workflows further using Inventor Stress Analysis, referto other Help documents and tutorials included with Inventor.


Previous (page 112)

Summary | 115

116

Frame Analysis

About this tutorial

Perform basic structural analysis of your frame structures with respect todeformations and stresses.

SimulationCategory


7

117

analyze_frame.iamTutorial File Used


The Frame Analysis environment is a special environment within assemblyand weldment files. The environment has commands unique to its purpose.You can access the tools from the Design or Environments tabs.

When you open a Frame Analysis and set up your simulation, the assemblyframe model is automatically converted to a simplified model of nodes andbeams. The graphics window displays beams, nodes, and the gravity glyph.

Then, you define the boundary conditions (consisting of loads and constraints).You can also change beam materials, and specify connections (releases andrigid links). Once these inputs are entered, you can run the simulation andview the behavior relative to the conditions you defined.

Objectives■ Create a simulation.

■ Evaluate and assign materials.

■ Evaluate and assign beam properties.

■ Add loads.

■ Add constraints.



Prerequisites■ Know how to use the Quick Access toolbar, tabs, and panels on the ribbon,

model browser, and context menus.

■ Know how to navigate the model space with the various view tools.


■ Complete the Frame Generator tutorial.

■ See the Help topics for further information.

118 | Chapter 7 Frame Analysis





Next (page 119)

Open the AssemblyTo begin, open the assembly to analyze.


2 Set the Project File to tutorial_files.ipj

3 Select Frame Analysis 1 ➤ analyze_frame.iam.

4 Click Open.

5 Click Save as to save the file with a different name, such as:analyze_frame_tutorial.iam.


Frame Analysis EnvironmentWe are ready to enter the Frame Analysis environment.

1 On the ribbon, click Environments tab ➤ Begin panel ➤ Frame

Analysis .

Initially, there are only three commands enabled: Create Simulation,Frame Analysis Settings, and Finish Frame Analysis. For now,create a simulation and review the settings in the next step.

2 On the Manage panel, click the Create Simulation command.The Create New Simulation dialog box opens.

You can use the dialog box settings to specify a unique name, simulationtype, and other simulation parameters.


There are two types of Frame Analysis.

■ Static Analysis evaluates structural loading conditions.

■ Modal Analysis evaluates natural frequency modes.

NOTE On the Model State tab, you specify the Design View,Positional, and Level of Detail to use for the simulation. Also, you canspecify the iAssembly member to be associated with the simulation. Thesettings can be different for each simulation.

3 Click OK to accept the default settings for this simulation.

The Inventor model is automatically converted into idealized nodes andbeams, and a simulation is created. A gravity symbol also displays.


Frame Analysis Environment | 121


Most of the commands in the ribbon panels are now enabled for use. Disabledcommands enable after you run the simulation.


Frame Analysis SettingsFrame Analysis settings apply to all new simulations. Whenever a new framesimulation is started, these preferences are used.

In the Frame Analysis Settings dialog box, you can specify:■ If Heads up Display is the preferred method used during input and edit.

■ Colors for displayed boundary conditions, nodes, rigid links, gravity.

■ Scale for displayed nodes, loads, and constraints.

■ Default visibility settings for all components (beams and other parts) afterthe conversion.

■ Solver method used for beam releases.

■ Display of diagrams.

In this tutorial, we use the dialog boxes for input of boundary conditionsvalues.

On the ribbon, click Frame Analysis Settings in the Settings panel.

In the General tab, clear the Use HUD in Application check box. ClickOK.


Assign MaterialsThe next step is to look at the model materials and adjust the material.

For this simulation, we only make a minor material change using materialsthat are fully defined.


Before you perform simulations, ensure that your material definitions arecomplete for those materials being analyzed. When a material is not completelyor inadequately defined, a warning message displays in the Status folder inthe browser. You cannot run a simulation until you change the material.

NOTE You cannot edit a material if the project setting Use Styles Library isset to Read-Only. To change the setting requires exiting the tutorial. In thistutorial, we use a material that is already fully defined. You can modify the othermaterials at a later time.

1 In the browser, expand the Beams folder, and select Beam:1. Right-clickand select Beam Materials. In the Beam Material dialog box, selectthe beam (DIN U 200 00000001.ipt) in the Beams area.

NOTE Beam Material dialog box is also accessible when you click Material

on the Beams panel in the ribbon.

2 Check the Customize box.

NOTE The Customize check box is only available when the parent beam isselected.

3 In the drop-down menu in the Material area, select Stainless Steel,Austenitic.

4 Click OK to exit the Beam Material dialog box.

The browser Materials folder receives a Stainless Steel, Austenitic - DINU 200 00000001.ipt folder added with all the components referencing thatmaterial listed within that folder. If you delete individual components fromthe folder, their material reverts to the assembly assigned material.



Change Beam PropertiesYou can also change beam properties.

1 In the Beams panel, click the Properties command. Thedialog box displays the list of beams, and basic and mechanical propertiesof a selected frame member.

2 To change the data, select the parent beam in the Beams area.

3 Check the Customize box to make the edits. In this tutorial, we do notcustomize any data.

4 Click Cancel to exit the Beam Properties dialog box.


Change Direction of GravityWhen a frame analysis is created, gravity is automatically applied. In thistutorial, we change its direction.

1 In the browser, expand the Loads folder. Select Gravity . Right-click,and select Edit.

2 In the Gravity dialog box, select Z Direction from the drop-down list.

3 Click OK to close the Gravity dialog box.



Add ConstraintsNext, we define the boundary conditions by adding structural constraints andloads. We start with constraints first.

NOTE Constraints are required for frame simulations. If you start a simulationwithout constraints, a dialog box displays the error message: No constraintsdefined.

1 In the Constraints panel, click Pinned . The dialog boxdisplays with the Origin selector active.

2 Select the beam as shown in the image. The preview of the pinnedconstraint displays.

Add Constraints | 125

3 Make sure the Absolute option is selected in the Pinned Constraintdialog box. We insert the offset value using the absolute values measuredfrom the beginning of the beam.


NOTE You can use the Local Systems command in the Displaypanel to show the beam coordinate systems to define the beginning of thebeams.

4 In the Pinned Constraint dialog box, set Offset to 170 mm, and clickOK. The Pinned constraint is applied.

5 Insert the second pinned constraint to the same beam. Again, click

Pinned in the Constraints panel.

6 Select the same beam, and set Offset to 2330 mm. Click OK.


Add Constraints | 127

Add Constraints to the Next BeamWe must insert pinned constraints to the opposite side of the cart.

1 In the browser, select Constraints folder. Right-click and select Pinned

Constraint .

2 Select the beam as shown in the following image. The preview of thepinned constraint displays.


3 In the Pinned Constraint dialog box, set Offset to 170 mm, and clickOK. Pinned constraint is applied.

4 Insert the second pinned constraint to the same beam. In the browser,select Constraints folder. Right-click and select Pinned Constraint

.

5 Select the same beam, and set Offset to 2330 mm. Click OK.

We applied all necessary constraints so we can add loads now.


Add LoadsNow assign loads on the components.

1 In the Loads panel, click Force . The dialog box displays withthe Origin selector active.

Add Loads | 129

2 Select the middle beam where the force is acting.

3 In the dialog box, enter 500 N for the Magnitude value, and 0 degreesfor Angle of Plane.

NOTE The Angle of plane specifies the rotation of the XY plane where theforce is acting. Angle in plane defines the angle of the applied force fromthe Z-axis.

4 Click the More button to expand the dialog box to display additionalcontrols for specifying the force vector. In the Offset area, check theRelative box. You can now position the force to the middle of theselected beam. Enter 0.5 in the Offset edit field in the upper part of the


dialog box. Click OK to exit the Force dialog box.



In the Solve panel, click Simulate . The progress bar displaysshowing the status of the simulation.



View and Interpret Results

After the simulation completes, the graphics window displays the Displacementresults plot, by default. Expand the Results folder to explore the completeset of results.

There are various commands for viewing result data. Most are located in theResult and Display panels.

Save the assembly. You use this assembly in the Frame Analysis Resultsand Modal Type of Frame Analysis tutorials.



Summary

The previous image is what you see if you look at the Fx Forces results for thissimulation.

Now you have a basic understanding of the typical workflow in the frameanalysis environment. This workflow includes:■ Creating a simulation.

■ Assigning materials as overrides of the existing material.

■ Adding constraints and loads, sometimes called boundary conditions.

■ Running a simulation.

■ Viewing the results.

What Next? As a next step, explore the tools available for viewing andinterpreting results. The Frame Analysis Results tutorial takes you throughthese topics.

Summary | 133

Previous (page 132)


Frame Analysis Results

About this tutorial

SimulationCategory


analyze_frame_tutorial.iamTutorial File Used

8

135


Objectives■ Open a simulation.


■ Display and edit diagrams.

■ View beam detail.

■ Adjust displacement display.

■ Display maximal and minimal values in the graphics window.

■ Animate results.

■ Generate report.

Prerequisites■ Complete the Frame Analysis tutorial.

■ Know how to use the Quick Access toolbar, tabs and panels on the ribbon,model browser, and context menus.





Next (page 136)

Get StartedTo begin, open the assembly to analyze.



3 Select Frame Analysis 1 ➤ analyze_frame_tutorial.iam.

136 | Chapter 8 Frame Analysis Results



NOTE This assembly was created during Frame Analysis tutorial.

4 Click Open.



On the ribbon, click Environments tab ➤ Begin panel ➤ Frame Analysis

.

We created a simulation during the Frame Analysis tutorial so the modelwith simulation results displays. The displacement results plot displays in thegraphics window by default.



All the commands in the ribbon panels are now enabled for use. We can usethe commands for viewing and interpreting results.



View and Interpret the Results

In the browser, expand the Results folder.

The Results folder includes results for Displacement, Forces, Moments, NormalStresses, Shear Stresses, Torsional Stresses, and the Diagrams folder.

Expand a folder and double-click to display the particular result.

When there are any errors or warnings during a simulation, they display inthe Status folder. Our simulation ran without any problems, so the Statusfolder is empty.

We now explore various tools located in the Result and Display panels forviewing result data.



Display Maximum and Minimum ValuesMinimum and maximum values quickly show the locations of load extremes.

In the Display panel, click Max Value . In the graphics window, alabel with a leader points to the location of the maximum value.

In the Display panel, click Min Value . In the graphics window, alabel with a leader points to the location of the minimum value.

NOTE You can drag the labels to different locations.

The following image shows maximum and minimum values for theDisplacement results plot.


Cancel the selection of the Max Value and Mix Value options in the Displaypanel to hide the values.


View Beam DetailYou can display detailed results for the selected beams. In the Result panel,

click Beam Detail .

First, select a beam whose results you want to display. Select a beam as shownin the following image.

View Beam Detail | 141

In the Diagram Selection area, select the result data you want to displayas a diagram. Select a particular force, moment, or stress to display its diagram,Fz for example. The displayed diagram is for viewing only and cannot beedited.

A complete list of beam results displays on the right side of the dialog box.

Click OK to close the dialog box.


Display and Edit DiagramsTo display results for a given beam, you can add user-defined diagrams to the

graphics window. In the Result panel, click Diagram .


In the Beams area, select how you want to specify which beams are includedin the diagrams. In this tutorial, check the Selected Beams box, and selectthe beam as shown in the following image.

Now, select which results you want to display. Check the Fx and Fy boxes inthe Loads area.

Display and Edit Diagrams | 143

Click OK to close the Diagram dialog box.

You can adjust the display of beam diagrams in the Diagram Scales dialogbox. In the browser, select Diagrams, right-click, and select Diagram Scales

. Use the Expand, Contract, and Normalize buttons to adjust the scale ofdiagrams. Click OK to see the change in the scale in displayed diagrams.


Adjust Displacement DisplayYou can scale the model deformation using the options in the AdjustDisplacement Display drop-down list in the Display panel.

Expand the Results folder, and double-click the Displacement browser node.


Select a multiple to improve the view of the deformation of the model.

In the following image, the Adjusted x0.5 option is selected.

In the following image, the Adjusted x5 option is selected.

Adjust Displacement Display | 145


Animate the ResultsNow, create an animation of the results.

1 Click Animate in the Result panel.

2 In the Animate Results dialog box, specify number of steps. Set the Stepsedit field to 8.

3 Specify the playback speed. Select Normal in the Speed drop-downmenu.

4 Click the Play command to see the animation. You can pauseplayback.


5 When you finish the displacement animation, click OK to exit theanimation playback.

The Animate Results dialog box also has options for displaying the originalwireframe with the plot. You can also record the animation to present or retainfor records.


Generate ReportWe can generate a report of the simulation results which includes all thesimulation data and outputs.

1 Click Report in the Publish panel.

2 On the General tab, check the Custom box.

3 Switch to the Simulations tab, and make sure the Material and CrossSection in the tree are selected.

4 Switch to the Format tab and make sure the Web page – multiplefiles (.html) option is selected in the Report Format drop-down menu.

5 Click OK to close the dialog box and create the HTML report.

Report contains text and PNG images that represent a static snapshot of theanalysis results.


Generate Report | 147

Summary

Now you have an understanding of the tools you can use to view and interpretresults of frame analysis. You know how to:■ Display and edit diagrams.

■ View beam detail.

■ Adjust displacement display.

■ Display maximal and minimal values in the graphics window.

■ Animate results.

■ Generate report.

What Next? As a next step, look into creating advanced connections (releasesand rigid links), and adding custom nodes to the beam model. The FrameAnalysis Connections tutorial takes you through these topics.

Previous (page 147)


Frame Analysis Connec-tions

About this tutorial

Add and define connections to simulate interactions between assemblycomponents in Inventor Frame Analysis.

SimulationCategory

9

149


analyze_frame.iamTutorial File Used


Prerequisites

Familiarize yourself with the Frame Analysis environment by doing the FrameAnalysis and Frame Analysis Results tutorials.



Next (page 150)

Connections OverviewIn the analysis of a frame assembly, you create connections to define therelationship between beams. Connections transfer load between beams whilepreventing beams from penetrating each other. Connections can simulateinteraction between beams that separate or come into contact during loading.Without connections, beams do not interact with each other in the simulation.

There are two connection types you can use to simulate the physical behaviorof a frame assembly.

Rigid links are used to model rigid elements of elastic structures (definitionof a rigid body in a structure). Displacements and rotations defined for a rigidlink can be limited to certain selected degrees of freedom.

You need at least two nodes to define a rigid link, one parent node and oneor more child nodes. A parent node passes its parameters down to child nodesduring simulation.

Releases of specified degrees of freedom can be applied to start or the end ofthe beam with possible elasticity.


150 | Chapter 9 Frame Analysis Connections



Open the AssemblyTo begin with, we open the assembly to analyze.



3 Select Frame Analysis 1 ➤ analyze_frame.iam.

4 Click Open.

5 Click Save as to save the file with a different name, such as:analyze_frame_connections.iam




1 On the ribbon, click Environments tab ➤ Begin panel ➤ Frame

Analysis .

2 On the Manage panel, click the Create Simulation command.The Create New Simulation dialog box displays.

3 Switch to the Model State tab. In the Design View drop-down menu,select Default. the default view displays the complete assembly thatwe want to analyze.

4 Click OK to close the dialog box.

The Inventor model is automatically converted into idealized nodes andbeams, and a simulation is created. The Gravity symbol also displays.




Most of the commands in the ribbon panels are now enabled for use. Disabledcommands enable after you run the simulation.


Change Direction of GravityWhen a simulation is created, gravity is automatically applied. In this tutorial,we change the direction of gravity.

1 In the browser, expand the Loads folder. Select Gravity . Right-clickand select Edit.

2 In the Gravity dialog box, select Z Direction from the drop-down list.

3 Click OK to close the Gravity dialog box.


Add Custom NodesNext, we add nodes to the selected beams of the frame structure. Customnodes are used for defining the loads, constraints, releases, and rigid links.

1 In the Connections panel, click Custom Node . A Heads UpDisplay (HUD) is used as the default edit method. It prompts you toselect a beam where we place the custom nodes.


2 Select the beam as shown in the following image.

3 Enter 170 mm to the Offset edit field and click Done . Repeat thesame steps to insert a second custom node to the same beam. Click theCustom Node command, select the beam, enter 2330 mm and click

Done .

4 Now, we insert custom nodes to the parallel beam. In the Connections

panel, click Custom Node .

Add Custom Nodes | 155

5 Select the beam as shown on the image.

6 Enter 170 mm to the Offset edit field and click Done . Repeat thesame steps to insert a second custom node to the same beam. Click theCustom Node command, select the beam, enter 2330 mm and click

Done .



Add Custom NodesWe also insert custom nodes to the rails under the cart wheels. Later, we useall these nodes to create rigid links.

1 In the Connections panel, click Custom Node .


3 Enter 6080 mm to the Offset edit field and click Done . Insert asecond custom node to the same beam. Right-click and select RepeatCustom Node. Select the same beam, enter 3920 mm and click Done

.

Add Custom Nodes | 157

4 Now, we insert custom nodes to the parallel beam. In the Connections

panel, click Custom Node .


6 Enter 6080 mm to the Offset edit field and click Done . Insert asecond custom node to the same beam. Right-click, and select RepeatCustom Node. Select the same beam, enter 3920 mm and click Done

.

We inserted all custom nodes that we need for our analysis. Custom Nodesare listed in the Nodes folder in the browser. Their numbers were assigned inthe order we defined them, starting from the first available node number.


NOTE You can also display the node numbers in the graphics window. In the

Display panel, click Node Labels .


Change Color of Custom NodesWe can graphically differentiate custom nodes in the graphics window.

1 On the ribbon, in the Settings panel, click Frame Analysis Settings

.

2 On the General tab, in the Colors area, click the arrow button next tothe Custom Nodes field.

3 On the Color dialog box, select a color for custom nodes. Select a red

color , and click OK to save the changes and exit the Color dialogbox.

Change Color of Custom Nodes | 159

4 Click OK in the Frame Analysis Settings dialog box. All custom nodesnow display in red color in the graphics window.


Assign Rigid LinksNow we define the rigid links to create connections between selected nodes.We create rigid links between nodes located under and above the cart wheels.

1 In the Connections panel, click Rigid Link .


2 The Parent Node button is automatically activated. Select the node asshown in the following image:

Assign Rigid Links | 161

3 The Child Nodes button activates. Select the node as shown on theimage:

4 On the Rigid Link dialog box, in the Rotation area, clear the Y-Axischeck box. The Rigid link is free to rotate about the Y-axis. Click Apply.

5 The Rigid Links dialog box remains open after we create our first rigidlink. Define rigid links between nodes under and below remaining threecart wheels. Always, select the node below the wheel as a parent node,and a node above the wheel as a child node. For all rigid links, clear theY-Axis check box in the Rotation area. In the image, see which nodes toselect to create rigid links. When you define the last rigid link, click OK


to close the Rigid Link dialog box.

Assign Rigid Links | 163

6 Now, four new rigid links are created between selected custom nodes.


Add ConstraintsThe simulation cannot be successfully performed without constraints. Weinsert constraints to four edge nodes on rails.

NOTE Constraints are required for frame simulations. If you start a simulationwithout constraints, a dialog box opens and displays the error message: Noconstraints are defined.

1 In the Constraints panel, click Fixed .


2 You are prompted to select an origin of the fixed constraint. Select anyof the nodes at the end of rails. Order is not important because we insertfixed constraints to all these four nodes as shown in the following image.

NOTE A symbol is displayed at the node when the constraint is applied, anda node is added to the browser.

3 After you apply the first fixed constraint, right-click and select RepeatFixed Constraint. Select another node at the end of beam rails. Usethis method to place fixed constraints to all four nodes at the ends ofrails. You can zoom in the graphics window to see if constraints areapplied.






View the Results

After the simulation completes, the graphics window displays the Displacementresults plot. The complete set of results is posted in the Results folder.


The status messages about the simulation display in the Status folder. Oursimulation ran without any problems or errors so the Status folder is empty.

There are various commands for viewing result data. Most of them are locatedin the Result and Display panels.


Assign a ReleaseWe now assign a release with free rotation to one of the rails below the cart.Notice that it gets much more deformed than the opposite rail.

1 In the Connections panel, click Release .

Assign a Release | 167

2 Select the beam as shown in the image.

A beam coordinate system is shown while editing, closer to the start endof the beam. Also, symbols of degrees of freedom at start and end nodeof the beam display. The following symbols are used:

■ x means a “fixed” type of displacement or rotation

■ f means an “uplift none” type of displacement or rotation

■ f+ means an “uplift+” type of displacement or rotation

■ f- means an “uplift-“ type of displacement or rotation

3 In the Release dialog box, the uplift none options are set for all threerotational axes. Rotation is free to move in all directions. Accept the


default settings, and click OK to assign a release to the selected beam.


Run the Simulation AgainBecause we changed the inputs for our simulation, there is a browser icon

next to the Results browser node. It indicates that results do not reflectcurrent inputs.

We must rerun the simulation to update results.

Run the Simulation Again | 169



View the Updated Results

After the simulation completes, the graphics display presents the Displacement

results plot. Also, the icon disappeared from the Results browser node.The results now reflect current inputs and simulation properties.


You can see that the released rail is more deformed that the opposite railwithout a release.


Summary

Now you have a basic understanding of how to work with a connection inframe analysis. You learned how to:■ Create a simulation.

■ Change direction of Gravity.

■ Add custom nodes.

Summary | 171

■ Assign rigid links.

■ Set the degrees of freedom of rigid links.

■ Assign releases.


■ Viewing and interpreting the results.

What Next? As a next step, look into creating a modal type of frame analysis,and interpreting the modal frequencies. The Modal Type of Frame Analysistutorial takes you through these topics.

Previous (page 170)


Modal Type of FrameAnalysis

About this tutorial

10

173

Perform a structural frequency (modal analysis) study to find natural modeshapes and frequencies of vibration.

SimulationCategory


analyze_frame_tutorial.iamTutorial File Used


The tutorial uses an Inventor assembly with frames and demonstrates theprocess of creating, solving, and viewing results. We use 3D plots to illustratethe various mode shapes and corresponding frequency values.

Objectives■ Create a modal simulation.

■ Change simulation properties.

■ Exclude components from simulation.



■ Create an animation of results.

Prerequisites■ Complete the Frame Analysis tutorial.




Next (page 175)

174 | Chapter 10 Modal Type of Frame Analysis



Open the AssemblyTo begin, we open the assembly to analyze.



3 Select Frame Analysis 1 ➤ analyze_frame_tutorial.iam.

NOTE This assembly was created during the Frame Analysis tutorial.

4 Click Open.

5 Click Save as to save the file with a different name, such as:analyze_frame_modal_type.iam


Frame Analysis EnvironmentEnter the Frame Analysis environment.

On the ribbon, click Environments tab ➤ Begin panel ➤ Frame Analysis

.


Create a Simulation StudyThe Frame Analysis environment activates.

We created a simulation during the Frame Analysis tutorial so the modelwith simulation results displays. The Displacement results plot displays in thegraphics window, by default.


We change the simulation properties and create a modal analysis.

1 In the browser, select Simulation:1. Right-click, and select EditSimulation.

2 In the Edit Simulation Properties dialog box, select Modal Analysis.Click OK.


Run the Simulation

Because we changed the simulation properties, there is a browser icon next to the Results browser node indicating that results do not reflect currentinputs.


We must rerun the simulation to updatethe results.



View the Results

After the simulation completed, the icon disappeared from the Resultsbrowser node. The results now reflect current inputs and simulation properties.

Also, a Modal Frequency folder was created under the Results browsernode.

Expand the Modal Frequency folder to expose the list of available ModeShapes corresponding to each calculated natural frequency. Double-click thefrequency of choice to display it.

The following image shows the first three modal frequencies of the performedanalysis.



Animate the ResultsNow you can perform post-processing tasks using the Result panel commands.These commands are described in Help.

Create an animation:

1 Click Animate in the Result panel.

2 In the Animate Results dialog box, specify the number of steps. Set theSteps edit field to 8.

3 Specify the playback speed. Select Normal in the Speed drop-downmenu.

4 Click the Play command to see the animation. You can pause theplayback.

5 When you finish the displacement animation, click OK to exit theanimation playback.

The Animate Results dialog box has options for displaying the originalwireframe with the plot. You can also record the animation to present or retainfor records.



Summary

In this tutorial, you performed a structural frequency (modal analysis) analysiswith the goal of finding natural mode shapes and frequencies of vibration.The steps performed include:■ Create a modal simulation.

■ Change simulation properties.

■ Exclude components from simulation.



■ Create an animation of results.

Previous (page 178)

Summary | 179

180

Dynamic Simulation -Part 1

About this tutorialSimulate and analyze the dynamic characteristics of an assembly in motionunder various load conditions.

SimulationCategory


Reciprocating Saw.iamTutorial File Used

NOTE Click and read the required Tutorial Files Installation Instructions atht-tp://www.autodesk.com/inventor-tutorial-data-sets . Then download the tutorial datasets and the required Tutorial Files Installation Instructions, and install the datasetsas instructed.

Dynamic Simulation contains a wide range of functionality and accommodatesnumerous workflows. This tutorial helps you become familiar with the keyparadigms and features of Dynamic Simulation. Then you can explore othercapabilities, and apply Dynamic Simulation to your particular needs.

Objectives■ Recognize the differences between the Dynamic Simulation application and

the regular assembly environment.

■ See how the software automatically converts mate assembly constraints toDynamic Simulation standard joints.

11

181



■ Use Color Mobile Groups to distinguish component relationships.

■ Manually create rolling, 2D contact, and Spring joint types.

■ Define joint properties.

■ Impose motion on a joint and define gravity.

■ Use the Output grapher.

■ Run a dynamic simulation to see how joints, loads, and componentstructures interact as a moving, dynamic mechanism.

Prerequisites■ Complete the Assemblies tutorial.

■ Understand the basics of motion.




Next (page 182)

Open the Assembly1 To begin, set your active project to tutorial_files.

2 Open Dynamic Simulation 1 and 2 ➤ Reciprocating Saw.iam.

182 | Chapter 11 Dynamic Simulation - Part 1

3 Click ➤ Save As. Use RecipSaw-tutorial_1.iam for thename.

4 Click Save.

As you work through the following exercises, save this assembly periodically.


Degrees of FreedomBefore going further in the tutorial, it is good to understand the differencesbetween the assembly modeling and dynamic simulation environments.

Though both environments have to do with creating mechanisms, there aresome critical differences between Dynamic Simulation and the Assemblyenvironment. The basic difference has to do with degrees of freedom and howthey are managed.

In the assembly environment, unconstrained and ungrounded componentshave six degrees of freedom.

You add constraints to restrict degrees of freedom. For example, adding oneflush constraint between this part and one of its canonical planes removes 3degrees of freedom.

Degrees of Freedom | 183

In Dynamic Simulation, unconstrained and ungrounded components havezero degrees of freedom and will not move in a simulation. The addition ofjoints creates the degrees of freedom. When entering Dynamic Simulation,components that have mate constraints receive these joints automatically.

With either Dynamic Simulation or the assembly environment, the intent isto build a functional mechanism. Dynamic Simulation adds to that functionalmechanism the dynamic, real-world influences of various kinds of loads tocreate a true kinematic chain.


Automatic Constraint ConversionWhen you change from the assembly environment to the Dynamic Simulationenvironment, mate constraints are automatically converted into joints thatmatch the mechanical function of those constraints. You can accept the jointsas defined by the software, or you can modify or delete them as needed.

1 On the ribbon, click Environments tab ➤ Begin panel ➤

Dynamic Simulation.


NOTE If you are prompted to run the Dynamic Simulation Tutorial, clickNo.

The Dynamic Simulation environment is active. You will notice that thebrowser and its nodes have changed for the simulation environment.

In the simulation browser there are several folders for simulation objects.They relate to the simulation as follows:

Components with no degrees of freedomGrounded folder

Components with degrees of freedom allowing them to participate inthe simulation when forces are applied.Each mobile group is assigned a specific color. Right-click the MobileGroups folder and click Color Mobile Groups to visually determine mobilegroups the component resides in.

Mobile Groups folder

Joints created by automatic constraint conversion when entering thedynamic simulation environment. Contributing constraints are displayedas child nodes.

Standard Joints folder

All non-standard joints that are created reside in folders for those specificjoint types. Contributing constraints are displayed as child nodes.

Various Joint folders

Loads that you define, including Gravity, are displayed in this folder.External Loads folder

NOTE Assemblies containing legacy, pre-Inventor 2008, Dynamic Simulationobjects DO NOT have their constraints automatically converted upon enteringthe simulation environment.

2 Expand the Standard Joints folder.

Automatic Constraint Conversion | 185

These joints were automatically created based on the assembly constraintscheme. The software analyzes mate constraints and determines whichjoint will best equate with the constraint scheme.

You can disable the automatic conversion of constraints, and thenmanually convert only those you want in the simulation. Note, however,that when you turn off automatic constraint conversion, all existingjoints are deleted, including manually created joints, thereby removingall degrees of freedom.

To disable automatic constraint conversion, click Dynamic Simulation

tab ➤ Manage panel ➤ Simulation Settings. Clear thecheck mark next to Automatically Convert Constraints toStandard Joints so that this option is no longer active. Click Yes,when prompted, then click OK on the dialog box. All joints in theassembly are deleted.

To turn automatic constraint conversion back on, click the Simulation

Settings command and check the Automatically ConvertConstraints to Standard Joints option.

3 Click OK. Standard joints are created.

NOTE If you previously created non-standard joints in this assembly, thesejoints are deleted.

4 Expand the Mobile Groups folder.

Components whose constraint scheme displays controlled motion haverelationships built and are grouped based on the relationship.

5 Expand the Welded Group folder.

Where a rigid relationship exists between components the software maycreate a welded group. There are no degrees of freedom between themembers of a welded group.

6 Right-click the Mobile Groups folder, and click Color mobile groups.

All members within a group are assigned a color by the software. Thisfeature is used to easily identify members of a mobile group.

7 Right-click the Mobile Groups folder and click Color mobile groupsagain to turn off the group coloring.



Assembly Constraints1 To see a component move, click and drag the Bevel Gear1 component.

The motion you see is borrowed from the assembly environment. Eventhough you are in Dynamic Simulation, you are not yet running asimulation. Since a simulation is not active, the assembly is free to move.

NOTE Some motion associated with assembly constraints may not occurwhen doing this because those constraints are not automatically translatedinto joints.

2 In the Simulation Player floating window, click Run.

Assembly Constraints | 187

The Dynamic Simulation browser turns gray and the status slider on thesimulation panel moves, indicating that a simulation is running.

Although some joints were automatically created, the assembly displaysno motion. This is because of insufficient input at this point.

3 Click Stop if the slider is still moving.

Even though the simulation is not running, the simulation mode is stillactive. If you attempt to drag the Bevel Gear component, there is nomotion.

4 Click the Construction Mode command to leave the simulation runmode.

These relationships and behaviors may very well seem contradictory orconfusing. Don't be concerned. As you progress through the followingworkflows, Dynamic Simulation and its paradigms will be revealed.



Add a Rolling JointNow we need to build the relationship between the bevel gears.

There are two bevel gears, a larger one associated with the cam action, and asmaller one associated with the motor assembly. We will work with the smallergear to start with.

1 Expand the Mobile Groups folder and Motor node to reveal the BevelGear1 node.

2 Right-click the Bevel Gear node and click Edit.

You are automatically placed in the Part editing environment.

3 In the browser, expand the Surface Bodies(1) folder.

4 Right-click the Srf1 browser node, and click Visibility.

We will use the surface to help define the bevel gear relationship.

5 On the ribbon, click Return to go back to the simulationenvironment. Alternatively, right-click in the graphic area, and clickFinish Edit.

6 On the ribbon, click Dynamic Simulation tab ➤ Joint panel ➤

Insert Joint to display the Insert Joint dialog box.

7 In the drop-down list, select Rolling: Cone on Cone.

Add a Rolling Joint | 189

8 The component selector is automatically active, allowing youto begin selection. Select the Pitch diameter circle at the base of thesurface cone.

9 Click the component 2 selector , and select a conical faceon Bevel Gear2.

You may have to expand the Mobile Groups and Cam crank browsernodes to see the second gear.

10 Click OK.

11 Click and drag the motor bevel gear. The Cam crank assembly movesbecause of the joint you created.

12 Edit the part again, and turn off Visibility of the Srf1 surface body.


Building a 2D ContactThe next relationship that needs to be built is one between the cam FollowerRoller and the cam component. The Follower Roller needs to contact the cam.


Retaining degrees of freedom

The Follower Roller is a symmetrical part and, by default, dynamic simulationattempts to reduce symmetrical component movement. Why? An examplewill help.

Consider a wheel assembly. You have a tire mounted to a rim. That assemblyis attached to the vehicle with lug nuts.The function of a lug nut, forsimulation purposes, isn’t to revolve around its axis; it is to constrain theassembly to the vehicle. Because the lug nut is a symmetrical component, therotational degree of freedom (DOF) is automatically removed. This simplifiesthe model for simulation purposes. If you want to retain the lug nut’s rotationalDOF, you can do so using the Retain DOF command. The same is true inreverse. That is, you can use Ignore DOF to restrict the degrees of freedomof a component.

To ensure that the Follower Roller contacts the cam while also keeping itsdegree of freedom:

1 In the Mobile Groups folder, expand the Welded group. There aretwo components in the group.

2 Right-click the Follower Roller component, and click Retain DOF.

The roller retains its motion characteristics. Now, we need to make surethe roller contacts the cam.

3 Click the Insert Joint command to display the dialog box. From thelist, select 2D Contact.

4 Select the cam profile edge.

5 Select the sketch profile displayed on the roller component. As you cansee, you can use sketch geometry as part of the simulation.

Building a 2D Contact | 191

6 Click OK.

7 Drag the Follower until it contacts the cam. It makes contact but doesnot penetrate the cam. The 2D contact established a mechanicalrelationship between the two components.

Before going any further, we will modify the properties of the 2D contactand display the force vector.

8 In the browser, right-click the 2D contact joint, and click Properties.


9 Set the Restitution value to 0.0, and Friction to 0.15.

10 Expand the dialog box to access the lower section. Check theNormal box, and set the Scale to 0.003.

11 Click OK.


Add Spring, Damper, and Jack JointThe Follower is designed to slide through a portion of the Guide component.However, to hold the Follower Roller against the Cam, we must specify a

Add Spring, Damper, and Jack Joint | 193

spring between the Follower and Guide components. Dynamic Simulationoffers a joint for doing that and more - the Spring/Damper/Jack joint.

Depending on the joint type, the dialog box provides applicable inputs tohelp define the joint.

1 Click the Insert Joint command and in the dialog box, select Spring/ Damper / Jack from the drop-down list of joint types. TheComponent 1 selector is active.

2 On the Guide component, select the hole profile where the Followerpasses through the Guide.This creates one contact for the spring.

3 Select the edge profile where the spring will contact the follower.

4 Click OK.

The result is a spring joint in the browser and a graphic representationof a spring. The representation is deformable and has action-reactionforces, but does not have mass.


5 In the browser Force Joints folder, right-click the Spring joint, andclick Properties.

6 In the main section of the dialog box:■ Set Stiffness to 2.500 N/mm.

■ Set Free Length to 42 mm.

Expand the dialog box and set:

■ Set Radius to 5.2 mm.

■ Set Turns to 10.

■ Set Wire Radius to 0.800 mm.

7 Click OK. The spring properties and graphical display update.


Define Gravity1 In the browser External Loads folder, right-click Gravity, and then

click Define Gravity. Alternatively, you can double-click the Gravitynode.

If necessary, clear the check mark next to Suppress.

Define Gravity | 195

2 Select the Case edge as shown in the image to specify a vector for gravity.

You can use the Invert or Reverse command to changedirections.

3 Click OK.

Note that the direction of gravity has nothing to do with any externalnotion of "up" or "down," but is set according to the vector you specify.


Impose Motion on a JointTo simulate saw operation, it is necessary to impose motion. In this case, wewill apply motion to the motor, just as would be the real world case. To imposemotion, you must edit the joint properties.

1 In the browser Standard Joints folder, right-click the Revolution:2(Saw layout:1. Motor:1) joint, and click Properties.


2 Click the dof 1 (R) tab.

3 Click the Edit imposed motion command , and checkEnable imposed motion.

4 Click the arrow to expand the input choices, and click Constant Value.Specify 10000 deg/s (ten thousand).

5 Click OK.


Run a SimulationBecause the simulation is of a high speed device, we will modify the simulationproperties.

1 On the Simulation Player in the Final Time field, enter .5 s, whichis sufficient to demonstrate the mechanism.

TIP Use the tooltips to see the names of the fields on the Simulation Player.

NOTE The software automatically increases the value in the Images fieldproportionally to the change in the Final Time field. Press the Tab keyto move the cursor out of the Final Time field and update the Imagesfield.

2 In the Images field, enter 200. Increasing the image count improvesthe results we will view in the Output Grapher.

3 Click Run on the Simulation Player.

Run a Simulation | 197

As the Motor component drives the bevel gear, the remaining parts inthe kinematic chain respond.

Also, because we have not yet specified any frictional or damping forces,the mechanism is lossless. There is no friction between components,regardless of how long the simulation runs.

4 If the simulation is still running, click Stop on the Simulation Player.

Before leaving the simulation run environment, we’ll take a look at the OutputGrapher.


Using the Output GrapherThe Output Grapher is the means to examine a variety of results from thesimulation. The following list describes some of the things you can do afterrunning a simulation:■ Change reference frames to view results in various coordinate systems.

■ Display curve results.

■ Save the simulation results for later review and comparison.

■ Display results in terms of time or other criteria.

1 After running the simulation, but before leaving the run environment,on the ribbon click Dynamic Simulation tab ➤ Results panel ➤

Output Grapher .

The Output Grapher is divided into different sections: browser, graph,and time steps. Commands specific to Output Grapher are located on atoolbar across the top of the window. The window is resizable, so adjustit to meet your needs.

2 In the browser of the Dynamic Simulation - Output Grapher window,expand the Standard Joints node. Then, expand the Revolution:2node.

3 Under the Revolution:2 node, expand the Driving force node. Checkthe box next to U_imposed[1]. You will see the force displayed in thegraph region.

4 Expand the Prismatic:3 node.


5 Expand the Velocities node, and check V[1]. The velocity is presentedin the graph with the driving force.

6 Close the Output Grapher window.


Simulation PlayerLet's take a quick look at some features on the Simulation Player.

As mentioned, the Final Time field controls the total time available for asimulation.

Simulation Player | 199

The Images field controls the number of image frames available for a

simulation. Click Construction Mode , change this value to 100, andrun the simulation. Click Construction Mode when the simulation isfinished and change this value back to 200.

The Filter field controls the frame display step. If the value is set to 1, allframes play. If the value is set to 5, only every fifth frame displays, and so on.This field is editable when simulation mode is active, but not while asimulation is running.

The Simulation Time value shows the duration of the motion of themechanism as would be witnessed with the physical model.


The Percent value shows the percent complete of a simulation.

The Real Time of Computation value shows the actual time it takes torun the simulation. This is affected by the complexity of the model and yourcomputer's resources.

You can click Screen Refresh to turn off screen refresh during thesimulation. The simulation runs, but there is no graphic representation.

Simulation Player | 201

Click the Construction Mode command to exit the simulation runenvironment. The construction mode is where you create and edit joints.

IMPORTANT Save the assembly before exiting. This will enable you to go to thenext tutorial and use this assembly as the basis for that tutorial.


Summary

You can also export load conditions at any simulation motion state to StressAnalysis. In Stress Analysis, you can see, from a structural point of view, howparts respond to dynamic loads at any point in the assembly's range of motion.

In this tutorial, the skills you learned include:■ Understanding basic differences between the Dynamic Simulation

application and the regular assembly environment.

■ Having the software automatically convert relevant assembly constraintsto Dynamic Simulation standard joints.

■ Use Color Mobile Groups to distinguish component relationships.

■ Manually creating rolling, 2D contact, and Spring joint types.

■ Defining joint properties.

■ Imposing motion on a joint and defining gravity.

■ Using Output graphers.


■ Running a dynamic simulation to see how joints, loads, and componentstructures interact as a moving, dynamic mechanism.

Remember to check the Help files for further information. And, remember togo online at autodesk.com for more tutorials and Skill Builders.

Previous (page 199)

Summary | 203

204

Dynamic Simulation -Part 2

About this tutorial

Add the blade assembly and complete the operating conditions definition,modify the cam lobe, and then publish the simulation with Inventor Studio.

SimulationCategory


Used in the tutorial:Tutorial Files UsedRecipSaw_tutorial_1.iamBlade set.iam

12

205

Completed file:Reciprocating Saw FINAL.iam


In this tutorial, we pick up where we left off in the Dynamic SimulationFundamentals - Part 1 tutorial.

Objectives■ Add the saw blade subassembly.

■ Add various joints.

■ Impose motion, friction, and retain degrees of freedom in subassemblies.

■ Add traces.

■ Publish a simulation animation using Inventor Studio.

Prerequisites■ Complete the Dynamic Simulation Fundamentals - Part 1 tutorial.

■ Complete the Studio - Animations tutorial.

■ Understand the basics of motion.




Next (page 206)

Work in the Simulation EnvironmentUnderstanding Simulation Commands

Large and complex moving assemblies coupled with hundreds of articulatedmoving parts can be simulated. The Autodesk Inventor Simulation provides:■ Interactive, simultaneous, and associative visualization of 3D animations

with trajectories; velocity, acceleration, and force vectors; and “deformable”springs.




■ Graphic generation command for representing and post-processing thesimulation output data.

Simulation Assumptions

The dynamic simulation commands provided in Autodesk Inventor Simulationhelp in the steps of conception and development and in reducing the numberof prototypes. However, due to the hypothesis used in the simulation, it onlyprovides an approximation of the behavior seen in real-life mechanisms.

Interpreting Simulation Results

To avoid computations that can lead to a misinterpretation of the results orincomplete models that cause unusual behavior, or even make the simulationimpossible to compute, be aware of the rules that apply to:■ Relative parameters

■ Coherent masses and inertia

■ Continuity of laws

Relative Parameters

The Autodesk Inventor Simulation uses relative parameters. For example, theposition variables, velocity, and acceleration give a direct description of themotion of a child part according to a parent part through the degree of freedom(DOF) of the joint that links them. As a result, select the initial velocity of adegree of freedom carefully.

Coherent Masses and Inertia

Ensure that the mechanism is well-conditioned. For example, the mass andinertia of the mechanism should be in the same order of magnitude. The mostcommon error is a bad definition of density or volume of the CAD parts.

Continuity of Laws

Numerical computing is sensitive toward discontinuities in imposed laws.While a velocity law defines a series of linear ramps, the acceleration isnecessarily discontinuous. Similarly, when using contact joints, it is better toavoid profiles or outlines with straight edges.

NOTE Using little fillets eases the computation by breaking the edge.


Work in the Simulation Environment | 207

Construct the Operating ConditionsWe will now complete the motion definitions so that the simulation reflectsproduct operating conditions.

If the RecipSaw-tutorial_1.iam assembly is not open, open the file to continue.As you can see, although we have the saw body, we do not have the bladecomponents. To add the blade components it is not necessary to leave thesimulation environment.

NOTE Make sure you are in Construction Mode before performing the next steps.

1 Click the Assemble tab to display the Assembly ribbon.

2 In the Component panel, click Place Component. Select DynamicSimulation 1 and 2 ➤ Blade set.iam and click Open.

3 Position the Blade set assembly near where it will be assembled.

4 Right-click in the graphics window, and click Done.

5 In the browser, expand the Blade set assembly node to display thecomponents.


6 Select the Scottish Yoke component. In the Quick Access toolbar,change the appearance to Chrome.

NOTE If you receive an Associative Design View Representation messageabout appearance associativity, select Remove associativity and clickOK.

7 Add a Mate constraint between the Scottish Yoke and the Guide toposition the yoke on top of the guide.

8 Add a second Mate constraint between the two components to positionthe yoke within the guide rails. Notice that in the simulation browser,under Standard Joints, a prismatic joint was created based on addingthose constraints.

Construct the Operating Conditions | 209


Add FrictionThe mechanism thus far is lossless; meaning that it operates without frictionor dampening as would normally be experienced. We will now add frictionto capture the operating environment.

Add Friction and complete the yoke-guide relationship

1 In the browser, right-click Blade set.iam, and click Flexible. By settingthe assembly to Flexible, the assembly is placed into the welded groupfolder. Within that assembly, the constraints are evaluated and theconstraint between the yoke and blade causes the addition of aRevolution joint.


2 As previously mentioned, the assembly has no friction yet. This stepimposes friction on the prismatic joint. Right-click the Prismatic Jointfor the Guide and the Scottish Yoke, and click Properties.

3 Click the dof 1 (T) tab.

4 Click the Edit joint force command .

5 Click Enable joint force.

6 Enter a Dry Friction coefficient of 0.1, and click OK.

7 Now, you must add a constraint to position the Scottish Yoke with respectto the crank assembly. First, set the browser view to Model, and expandthe Blade set.iam node.

8 Expand the Scottish Yoke node, and click the Constrain command.

9 In the browser, select Work Plane3 under the Scottish Yokecomponent.

10 In the graphics window, select a circular edge of the Roller componentthat is part of the Crank cam assembly. A Point-Plane joint is added toreflect the constraint.

Add Friction | 211

11 Click OK to add the constraint and close the dialog box.

12 Set the browser view back to Dynamic Simulation.

The resulting Point-Plane joint has five degrees of freedom and one constraint.It is enough definition to transfer motion without over constraining the model.Dynamic Simulation detects over-constrained conditions and helps you toresolve them.


Add a Sliding JointThe interface between the Blade set and the saw drivetrain is not yet completelydefined. We must have the follower end interact with the Blade Clampcomponent. It requires a sliding joint.

1 The next joint to add is the one between the Blade Clamp and theFollower, so that the Follower travels in the blade clamp. If the DynamicSimulation tab is not active, select it.

2 Before creating the joint, it helps to lock the Prismatic Joint between theGuide and Follower components. This prevents the related componentsfrom moving and lets the solver work more efficiently.

Right-click the Prismatic:3 (Guide:1, Follower:1) joint, and clickLock dofs.


3 Add the sliding joint. To do this, click Insert Joint. In the drop-downlist, select Sliding: Cylinder Curve. For input 1, select the blade clampslot profile on which the Follower rides.

4 For input 2, select the Follower cylinder face that rides in the slot.Click OK.

5 Unlock the Prismatic Joint.

That completes this section on adding components and joints to the assembly.In this section, you learned about:■ Adding assembly components while in the simulation environment.

■ Adding assembly constraints and seeing them automatically create standardjoints.

■ Adding joints to simulate mechanical conditions within the assembly.


Use the Input GrapherThe Input Grapher provides a means of adding forces and torques that changeduring the simulation based on other independent variables.

Use the Input Grapher | 213

We will add an external force that is dependent on the velocity in the prismaticjoint between the Guide and Scottish Yoke. To provide a sense of the velocitywe use + or - values to define an opposite force.

1 In the browser, in Standard Joints, select the joint Prismatic(Guide:1, Scottish Yoke:1). Note that in the reference frames, whenthe velocity is positive, the reference frames point away from the bladeend. If the reference frames point toward the saw blade, you may haveto edit the joint to reverse the direction.

2 In the Load panel, click the Force command. Select a vertex of one ofthe saw teeth.


3 Click the Direction selector in the dialog box.

4 Select the top edge of the saw blade that is parallel with the blade motion.

5 Click the arrow on the Magnitude input control to display the listoptions, and click Input grapher.

The Input Grapher dialog box displays for the remaining steps.

6 Click the Reference selector, and in the Select Reference dialog box,expand Standard Joints > Prismatic (Guide:1, Scottish Yoke:1)

Use the Input Grapher | 215

to reveal the Velocities folder and contents. Click V(1) to specify velocityas variable for the graph X axis.

7 Click OK. Notice in the graph region the X axis of the graph shows thereference you just specified.

When navigating inside the graph region.

■ You can roll the mouse wheel, if you have one, to zoom in and out.

■ To Pan the graph, click and drag the middle mouse button or wheeland watch the cursor move around the graph region.


8 In the lower section of the Input Grapher, for the Starting Pointsection, set X1 = -10 mm/s and Y1 = 250 N.

9 In the Ending Point section, set X2 = -0.1 mm/s and Y2 = 250 N.

10 Double-click in the graph area to the right and below the second point.This adds a new point, effectively creating a section in the graph.

NOTE You can also right-click beyond the second point and click AddPoint to start a new section. To select the second section, click on the linebetween the points.

11 The Starting Point for the second section (X1, Y1) is the previoussection end point and is already set. To specify the second sectionEnding Point, set X2 = 0.0 mm/s and set Y2 = -250 N.

12 Add a third section to the right of the second section. To specify thethird section Ending Point, set X2 = 10.0 mm/s and Y2 = -250 N.

13 Click OK to close the Input Grapher.

14 Expand the dialog box and check the Display option at the bottom.You can also specify a different color to differentiate the force visually.

15 Click OK to accept the input and close the Force dialog box.

16 Run the simulation. Do not leave the Run environment.


Use the Output GrapherThe Output Grapher allows you to examine various results from the simulation.The following is a list of some of the things you can do after running asimulation:■ Display vectors for internal or external forces.

■ Change reference frames to view results in various coordinate systems.

Use the Output Grapher | 217

■ Display curve results.

■ Save the simulation results for later review and comparison.

■ Display results in terms of time or other criteria.

■ Display traces to visualize trajectory of component points.

Display Traces

1 After running the simulation, and before leaving the run environment,click the Output Grapher command.

The Output Grapher window is divided into different sections: browser,graph, and time steps. Output Grapher commands are located in a toolbaracross the top of the window. The window is resizable, so adjust it tomeet your needs.

2 Click Add Trace . The dialog box displays, and the Origin selectoris actively awaiting an input. Select the point at the end of the saw blade.

3 In the dialog box, check the Output trace value option and click

Apply.

4 Add two additional trace points along the saw blade in the same manner,and be sure to export the trace for each point.


5 Close the dialog box.

Set Trace as Reference

1 In the Output Grapher browser, expand Traces.

2 Expand Trace:1, and then Positions.

3 Right-click P[X], and click Set as Reference.

4 Use the Output Grapher Save command to save the Simulation.

5 Enter the name RecipSaw_tutorial_1.iam, and click Save.

6 In the grapher browser, right-click P[X] and uncheck Set as Reference.

7 Close the Output Grapher.

8 Click Construction Mode in the Simulation Player.

As you can see, you can save simulation data, make changes, and comparethe change results with the previous data.


Export to FEANext we will export motion loads and run a stress simulation on a component.Use the following process for every component you want to analyze in thestress analysis environment.

Select the component

Use the following process for each component you want to analyze in FEA:

1 Run the simulation.

2 Open the Output Grapher.

3 In the Output Grapher toolbar, click Export to FEA.

4 In the simulation browser, select Follower:1 and click OK. The dialogbox for selecting load bearing inputs is displayed.

Select faces

Three joint inputs are required to satisfy the motion requirements for exportingthe Follower component.

1 In the graphics window, select the long shaft of the Follower component,which satisfies the prismatic joint input.

Export to FEA | 219

2 In the dialog box, click Revolution 5.

3 Select the small shaft that is used with the Follower Roller.

4 In the dialog box, click the Spring joint.

5 In the graphics window, click the face where the spring contacts thefollower, and click OK.


Next, specify the time steps to analyze:

1 Click the Deselect all command in the Output Grapher toolbar.

2 Expand the Standard Joints, Revolution:5, and Force folders. ClickForce.

3 Expand the Force Joints, Spring / Damper / Jack joint, and Forcefolders. Click Force.

4 In the graph region, double-click a Force (Revolution) graph high pointyou want to analyze. In the time steps section above the graph, place acheck mark next to the corresponding time step.

Export to FEA | 221

5 Using the same method, select a low point of the Force (Revolution)values. Place a check mark next to its time step.


Import into Autodesk Inventor Stress Analysis

1 Click Finish Dynamic Simulation.

2 On the Environments tab, click Stress Analysis to open in the StressAnalysis environment.

3 In the Manage panel, click Create Simulation.

4 In the dialog box, under Static Analysis, select the Motion LoadsAnalysis option. The two list controls below the option are enabledand populated with the exported parts and time steps.

5 In the Part list, select the Follower component.

6 In the Time Step list, select a time step to analyze.

7 Click OK. The assembly updates to represent that time step and thenisolates the Follower component for analysis. You can observe symbolsrepresenting the various forces acting on the Follower.

8 Click Mesh Settings, then click Create Curved Mesh Elements.


9 In the Solve panel, click Simulate, and then click Run. Wait for thesimulation to complete.

10 Select from the various Results data to see how the component performsat that time step.

11 Click Finish Stress Analysis to exit the Stress Analysis environment.


Publish Output in Inventor StudioYou can publish the simulation in Inventor Studio and produce high qualityvideo output containing lighting, shadows, backgrounds, and so on.

1 Reenter the Dynamic Simulation environment and run the simulation.After running the simulation, do not leave the run environment.

2 In the Animate panel, click Publish to Studio.

Publish Output in Inventor Studio | 223

3 In the Studio environment, set up the following for your simulation:■ Camera position, type, and associated settings.

■ Lighting style and its associated settings.

■ Scene style and its associated settings.

■ Different appearances, if desired.

If you are not experienced with Inventor Studio, take time to completea Studio tutorial to get familiar with the animation commands it provides.Then, return to this part of the Dynamic Simulation tutorial and outputyour simulation to Studio.

4 Click the Animation Timeline command to display thetimeline.

5 Set the timeline slider to the time at which the animation action is toend, such as 2 seconds.

6 In the browser, expand the Animation Favorites folder. Right-clickthe Simulation Timeline parameter, and click Animate Parameters

.

7 Set the Action End value to 200 ul.

8 Click OK.

9 In Studio, add lighting and scene styles as needed. Create the cameraangles you will use and complete the preparation of your animation.

NOTE If you have not used Inventor Studio to create animations previously,you may want to do the rendering and animation tutorials, which cover theinformation for this step.

10 Click the Render Animation command .

11 On the General tab, the styles you set up are the active ones. If not,select them from the various lists.

12 On the Output tab, click the box next to Preview No Render. Itproduces a test render for reviewing the animation action. Click OK torender a preview.


13 Once you confirm the animation is playing like you want, cancel thePreview option and render the simulation final animation with lightingand scene styles. Click OK to render a realistic-looking simulation.

NOTE You may want to render images at a few different time positions toensure the lighting and scene styles look like you expect, then render theanimation.

14 Save the assembly.


SummaryIn this tutorial, we demonstrated a workflow to add components to an assemblywhile in the Dynamic Simulation environment. We added the blade assemblyand completed the operating conditions definition. Then we modified thecam lobe, and finally published the simulation with Inventor Studio.

In this tutorial, you:■ Added the saw blade subassembly.

■ Added various joints.

■ Imposed motion, friction, and retained degrees of freedom in subassemblies.

■ Added traces.

■ Published a simulation animation using Inventor Studio.

What Next? - As a next step, consider completing one of the followingtutorials:■ Assembly Motion and Loads for a Cam and Lobe simulation

■ FEA using Motion Loads for exporting Motion Loads to stress analysis

■ Studio - Renderings for great looking images

■ Studio - Animations for creating animations of your product

Previous (page 223)

Summary | 225

226

Assembly Motion andLoads

About this tutorial

Simulate a cam and valve assembly.

SimulationCategory

13

227


cam_valve.iamTutorial Files Used


In this tutorial, you simulate a cam, valve, and spring mechanism. Youdetermine the contact forces between the cam and valve, the forces in thespring, and the torque required to drive the cam.

In addition, you view the simulation results in the Output Grapher, and exportthe simulation data to Microsoft Excel.

Objectives■ Create a spring.

■ Create a 2D Contact joint.

■ Impose a motion.

■ Simulate dynamic motion.

■ View the simulation results.

■ Export the simulation results to Excel.

Prerequisites■ It is recommended that you first complete the Dynamic Simulation

Fundamentals - Part 1 tutorial.

■ Understand the basics of motion and how it affects your design.

■ Know how to set the active project, navigate in model space with variousview commands, and perform common modeling functions such assketching and extruding.

■ See the Help topic, Getting Started, for more information.



Next (page 229)

228 | Chapter 13 Assembly Motion and Loads



Open AssemblyTo begin:

1 Set the active project to tutorial_files.

2 Open Dynamic Simulation 3 ➤ cam_valve.iam.

Open Assembly | 229

3 Use Save As to save a copy of this file with the file namecam_valve_tutorial.iam.



Activate Dynamic Simulation1 On the ribbon, select Environments tab ➤ Begin panel ➤

Dynamic Simulation. The Dynamic Simulation tab displays inplace of the previous tab.

2 If you are prompted to run the Dynamic Simulation Tutorial, click No.

In the following pages, you specify the joints and forces necessary tocreate a simulation.


Automatic Joint CreationBy default, Dynamic Simulation automatically converts assembly constraintsto joints for assemblies created in the Autodesk Inventor 2008 or later releases.The Dynamic Simulation browser lists two joints: a revolution joint betweenthe cam and the support, and a prismatic joint between the valve and thesupport.

To complete the mechanism, you manually add a spring joint and a 2D contactjoint.

TIP Automatically created joints are maintained in the Standard Joints folder.Joints that you add otherwise, reside in other folders based on the joint type.

TIP To delete automatically created joints, on the ribbon click DynamicSimulation tab ➤ Manage panel ➤ Simulation Settings, and then removethe checkmark next to Automatically Convert Constraints to StandardJoints. Click No, when prompted, and click OK or Apply in the dialog box.


Activate Dynamic Simulation | 231

Define Gravity1 In the browser, under External loads, right-click Gravity, and then

select Define Gravity.

2 To define a vector for gravity, select one of the vertical edges of thesupport.

Click the image to play the animation.

3 If the direction arrow points up, click Invert Normal to flip thearrow.

4 Click OK.

5 Click Run on the Simulation Player. The valve responds to theforce of gravity and drops away from the mechanism.

6 On the Simulation Player, click Construction Mode .


Insert a SpringBefore you insert the spring, make an adjustment to the mechanism.

1 If you have not already done so, you must return to the Construction

Mode. In the Simulation Player, click Construction Mode .

2 In the browser, right-click the prismatic joint, and then selectProperties.

3 Select the dof 1 (T) tab.

4 In the Position field, enter 8 mm, and press the Tab key to update theassembly.

The valve moves so that the two reference frame origins are separatedby 8 mm.

5 Click OK.


6 On the ribbon, click Dynamic Simulation tab ➤ Joint panel

➤ Insert Joint.

7 Select Spring/Damper/Jack from the drop-down menu (the joint islocated near the bottom of the menu).

8 This joint requires two selections. Select the circular edge on the support.

9 Select the circular edge on the valve.

10 Click OK.

Insert a Spring | 233



Define the Spring Properties1 Expand Force Joints in the browser. Right-click the spring in the

browser, and remove the checkmark next to Suppress to make thespring active.

2 Right-click the spring, and select Properties.

3 Enter 1 N/mm in the Stiffness field.

4 Enter 50 mm in the Free Length field to put a small preload on thespring.

TIP Double-click the existing value in the input fields to select the entirestring.

5 Click More to expand the dialog box.

6 Enter 12 mm in the Radius field.

NOTE The values in the Dimensions and Properties fields affect onlythe appearance of the spring, not its physical properties.

7 Click OK.

Define the Spring Properties | 235


Run the Simulation1 Click Run on the Simulation Player to show the effect of the spring.

The valve oscillates slightly due to gravity and the spring preload.

2 Return to Construction Mode.



Insert a Contact JointNext, you add a joint between the cam and the valve.

1 Click Insert Joint.

2 Select 2D Contact from the drop-down menu.

3 Select the sketch loop on the cam lobe, as shown.

4 Select the sketch loop on the top of the valve stem, as shown.

Insert a Contact Joint | 237

NOTE Make sure that you select the sketch and not surrounding geometry.You may need to zoom in or use Select Other to select the loop.

5 Click OK.

The contact joint is created and added to the newly added ContactJoints group in the browser.



Edit the Joint Properties

1 Click the View Face command , and then select the front face ofthe cam.

2 In the browser, expand Contact Joints. Right-click 2D Contact, andselect Properties.

The Z axis of the cam points away from the cam. If the Z axis pointedinward, you would open the properties dialog box for the 2D contactjoint and invert the normal direction of the Z axis for the cam. Likewisefor the valve, if the Z axis pointed inward, you would invert the Z axis.

Edit the Joint Properties | 239

The fact that the Z axis points away from the cam indicates that it is theouter surface of the part rather than the inner surface of a hole or cut.In this case, the Z axis must always point out away from the part materialrather than into the part material.

3 Expand the dialog box, then select Normal, and set the scale to 0.003.

4 Select Tangential, and set the scale to 0.01.

5 Click OK.



Add Imposed MotionNext, you add an imposed motion to specify the required rotation of the cam.

1 In the browser, expand Standard Joints.

2 Right-click the revolution joint, and select Properties.

3 Click the dof 1 (R) tab.

4 Click Edit imposed motion.

5 Select Enable imposed motion.

6 In the Driving field, ensure that Velocity is selected.

7 Click the arrow next to the velocity input box, and then select Constantvalue.

8 Change the value to 360 deg/s.

9 Click OK.


View the Simulation Results1 Click Run on the Simulation Panel.

2 Allow the simulation to run.

3 On the ribbon, click Dynamic Simulation tab ➤ Results panel

➤ Output Grapher to activate the Output Grapher dialogbox.

4 In the Output Grapher browser, expandcam_valve_tutorial ➤ Contact Joints ➤ 2DContact ➤ Point1 ➤ Force, and then select Force[1][Z].

5 In the Output Grapher browser, expand cam_valve_tutorial ➤ ForceJoints ➤ Spring/Damper/Jack ➤ Force, and then select Force[Y].

Add Imposed Motion | 241


View the Simulation Results (continued)View the results in the graph.

1 Arrange the Output Grapher and the model until you can view bothsimultaneously.

2 Double-click anywhere within the graph. A vertical black line appears.

3 While the Output Grapher still has the focus, press the right and leftarrow keys on the keyboard to step through the simulation one timestep at a time. Observe both the graphical results and the model.



Export the Data

1 On the Output Grapher toolbar, click Export Data to Excel .

2 Click OK to accept the default chart output.

3 In the Save Value Filter, click OK to accept the default.

4 View the chart and data in Microsoft Excel, then close Microsoft Excel.Do not save the file.

5 On the Output Grapher toolbar, click Deselect All .

6 In the Output Grapher browser, expandcam_valve_tutorial ➤ Standard Joints ➤ Revolution:1(support:1, cam:1) ➤ Driving force, and then select U_imposed[1].

7 In the Simulation Player, click Run, and observe the graph and assemblyto see the correlation between the graph and the motion in the assembly.


9 You can close the assembly without saving changes.


Export the Data | 243

Summary

This tutorial provided an overview of how to link a cam and valve, how tocreate a spring device, and how to use the Output Grapher to view simulationresults.

You learned how to:■ Create a spring.

■ Create a 2D Contact joint.

■ Impose a motion.

■ Simulate dynamic motion.

■ View the simulation results.

■ Export the simulation results to Microsoft Excel.

Try applying what you have learned to models you create.

Previous (page 243)


FEA using Motion Loads 14

245

About this tutorial

Generate and export motion loads.

SimulationCategory


Windshield Wiper.iamTutorial File Used

246 | Chapter 14 FEA using Motion Loads


Use Dynamic Simulation to generate loads to export and use in Stress Analysis.

Objectives■ Export motion loads for use in stress analysis.

Prerequisites■ Complete the Dynamic Simulation - Part 1 tutorial.

■ Know how to set the active project, navigate the model space with thevarious view tools, and perform common modeling functions, such assketching and extruding.




Next (page 247)

Open Assembly File1 To begin, set your active project to Tutorial_Files.

2 Open Dynamic Simulation 4 ➤ Windshield Wiper.iam.

Open Assembly File | 247



3 On the ribbon, click Environments tab ➤ Begin panel ➤ Dynamic

Simulation to switch to the Dynamic Simulation environment.The dynamic simulation commands populate the ribbon bar.

4 If you are prompted to view the Dynamic Simulation tutorial, click No.

5 If a message warns that the mechanism is overconstrained, click OK.The redundancy is not important for the purposes of this tutorial.



Run a SimulationTo generate the motion loads, you run a simulation and then export the loadsto Stress Analysis.

1 Click the Run command on the Simulation Player to run the simulation.Allow the simulation to finish.

2 When the simulation finishes, click Output Grapher locatedon the Results panel.

You use the Output Grapher to select and export the motion loads.


Generate Time Steps1 In the Output Grapher browser, nested under Export to FEA, right-click

Time Steps, and then select Generate Series.

2 In the Generate Time Steps dialog box, enter 16 in the Number ofSteps field.

3 Ensure the Between Time Steps option is selected.

4 Take the default start time of 0 s.

5 Enter 4 s (the duration of this simulation) in the End field.

6 Click OK.

These values generate four load intervals per second, for four seconds.

The time step series is added to the Output Grapher browser.


Export to Stress Analysis1 On the toolbar located at the top of the Output Grapher, select the

Export to FEA command.

You are prompted to select a part to analyze.

Run a Simulation | 249

2 Select the Crank Sway part. You can orbit the assembly or use SelectOther to access the part.

NOTE You can select more than one part to export. You cannot select partswithin a subassembly unless the subassembly is set to Flexible.

3 In the Export to FEA dialog box, click OK.

Next, you specify the load bearing faces. For this part, the holes on eitherend of the arm contain the load bearing faces.

4 For the Point-Line joint, select the face as shown.


5 In the dialog box, select the Revolution joint to complete the field.

6 Select the other face as shown.

Export to Stress Analysis | 251

NOTE Alternatively, you could use the Automatic Face Selection option toallow the software to select the load-bearing faces automatically.

7 Click OK.

The loads are exported and ready for retrieval in Stress Analysis.




Use the Motion Loads in Stress Analysis1 In the Exit panel, click Finish Dynamic Simulation, then click

Environments tab ➤ Stress Analysis . The stress analysisenvironment becomes active.

2 Click the Create Simulation command.

3 In the Create New Simulation dialog box, on the Simulation Typetab, check the box next to Motion Loads Analysis.

4 In the Part list box, select the Crank Sway component. The list displaysall components that were exported to FEA.

5 Next, specify the Time Step to be analyzed. The Time Step list displaysall 16 time steps from the Dynamic Simulation environment. You choosethe time step to analyze.

Use the Motion Loads in Stress Analysis | 253

6 Click OK. The loads for the time step you specified are added to thebrowser, nested under the Loads node.

7 Click the Simulate command to run the solution.


8 When the simulation finishes, evaluate the results for that motioninterval.


Use the Motion Loads in Stress Analysis | 255

Generate a reportFinally, you can generate a report of the analysis results. The report pertainsto the selected time step at the time the report is generated.

1 In the Report panel, click Report.

2 In the Report dialog box, specify the information you want included inthe report.■ If you want a complete report, click OK and the report will proceed.

■ If you want only certain information in the report, click Customand then specify the content for the report.

The report displays in your internet browser or as a Word document,depending on the output format you select. The report and associatedfiles are saved to the location designated in the Report dialog box. Bydefault, this location is the same as the part or assembly you areanalyzing.

If you want to save multiple reports, do one of the following■ Use Save As in your internet browser to save a copy of each report.

■ Rename the report file and generate an additional report. Repeat asappropriate.



Summary

In this tutorial, you learned how to:■ Generate motion loads for a selected part.

■ Access and use those loads within Stress Analysis.

■ Generate reports of analysis results.

Remember to check Help for further information.

Previous (page 256)

Summary | 257

258

Index

C

coherent masses and inertia 207continuity of laws 207

D

dynamic simulationassumptions 207coherent masses and inertia 207continuity of laws 207

relative parameters 207results 207

O

Output Grapher 208, 217

R

relative parameters 207

259 | Index

260

Simulation Tutorials

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