deform 3d hot forming

DEFORM-3D Hot Forming Labs

Lab 1 Create a New Problem. Import and Manipulate Geometry

Basic information flowThe basic icons used in setting up every problem are the preprocessor data settings, andthe object data settings.

1: Object DataDefinition

2: PreprocessorData Settings

Object Tree

Preprocessor data

Includes (in order from left to right)• Simulation controls• Material library editing tool• Object positioning• Interobject relationships• Database generation

Create new problem

Create a problem named “Tee” and Open the preprocessor

Set simulation controls

Set simulation controls for “English Units”

This will be a hot forging, but for now, we will not consider temperature change, soSet simulation mode to “ isothermal” (deformation on, heat transfer off)

Exit simulation Controls

Set initial object conditions

The object type is Plastic

Initial object temperature will be 2150F

Import object geometry

Import TeeBillet.stl

Check the geometry

Investigate view manipulation tools

Display Icons

Note: Some of the display functions (Pan, Zoom, Magnify, and Rotate) have easykeyboard/mouse combination hotkeys that allow the user to quickly perform thesefunctions without any button clicking. These hotkeys are the same as those used in manysolid modeling packages.

Measure (Display � Measure)Measure tool displays:L vector lengthV X,Y,Z component of measured distanceS Starting pointE Ending point

Select (Display � Select)Displays details of vertex, node, element, or surface facet selected

Pan (Display � Pan)Shift + Left Mouse Button

Zoom (Display � Zoom)Alt + Left Mouse Button

Magnify (Display � Magnify)Ctrl + Alt + Left Mouse Button

Rotate (unconstrained) (Display � Magnify)Ctrl + Left Mouse Button

Rotation about the X-axis (Display � Rotate X)Currently, this rotation is about the screen-based X-axis which is in the plane of thescreen and points to the right.

Rotation about the Y-axis (Display � Rotate Y)Currently, this rotation is about the screen-based Y-axis which is in the plane of thescreen and points upward.

Rotation about the Z-axis (Display � Rotate Z)Currently, this rotation is about the screen-based Z-axis which is perpendicular to thescreen and points outward toward the user.

View Icons

View Tool Box Window (View � Tool Box Window)

View Tree Window (View � Tree Window)

Refresh (Viewport � Refresh)F2

View Fit (Viewport � View Fit)F3

View Back (Viewport � View Back)F4

View Orientation Icons

Isometric View

YZ Plane View

X-axis either pointing out of the screen (+) or into the screen (-)

XZ Plane View Y-axis either pointing out of the screen (+) or into the screen (-)

XY Plane View Z-axis either pointing out of the screen (+) or into the screen (-)

Model Icons

View shaded objects (Model � Shading)F5

View mesh only (Model � Mesh)F5

View shaded mesh (Model � Shaded Mesh)F7

View surface patch (Model � Surface Patch) (feature lines) only F8

Toggle button to turn (Model � +Surface Patch) surface patch on. This button will stay depressed so that surface patches can be shown in the Shaded, Mesh, or Shaded Mesh view settings. Click the button again to toggle surface patches off.

Save File and Exit

Save the keyword file using the File->Save option.

Note: All of the above explanations of the View Orientation icons are based on theassumption that the Z-axis is pointing upward when the model is viewed in theIsometric view. This is the default setting. If the user wants, he can go toDisplay � Screen Upward and select another direction to point upward.

Note: The above icons only change the appearance of the objects that are currentlyshown in the Display window. For example, if you are only showing the workpiece

and you click the button to view shaded mesh, then the workpiece will be shownwith shaded mesh. If you then turn on a die, the die will not have the shaded meshapplied to it

Note – the “ save” button at the bottom of the screen only saves the CURRENTOBJECT.

Exit the preprocessor

Lab 2 – Import Tools – Manipulate Object Display

Open existing problem

Open the file “Tee” in the preprocessor

Add objects

If an object named Top Die does not currently exist, using the “add object” icon belowthe object tree, add a new object. It will default to the name “ top die” . Set thetemperature to 300F.

Add one more object. It will default to the name “bottom die.” Set the temperature to300F for this object, as well.

Import tool geometry

Select “Top Die” from the object tree. Go to the “Geometry” screen and importTeeTop.stl.

Now select “Bottom Die” from the object tree and import the file TeeBottom.stl

Investigate object tree manipulationObject Display ModesDEFORM has 3 different object display modes:• Single Object mode – the selected object is displayed. All other objects are hidden• Multi Object mode – the selected object is displayed in solid color. All other objects

are transparent• User Object mode – the user can set the display mode (on, transparent, or off) for

each object independently.

Single object Mode

Multi object Mode

User object Mode

Figure 1: Detail of Object Tree showing object mode selection icons

Tree levels and functionsThe right mouse button menu has functions associated with each level of the object tree.The object tree levels are shown in Figure 2. Many of these features relate to topicswhich will be covered in later labs.

Problem dataObject dataMesh data

Material Data

Geometry Data

Figure 2: Levels in the object tree. Right mouse selections at each level accesses acontext appropriate menu.

The Problem Data menu contains the following commands:• Turn on all objects• Turn off all objects• Turn on all workpieces - Turns on any object which is not rigid. Turns off all rigid

objects)• Turn on all dies - Turns on any object which is rigid. Turns off all other objects)

Turn on transparency for all• Turn off transparency for all• Turn on backface for all - backface shows the interior or back surface of rigid objects• Turn off backface for all

The Object Data menu contains some or all of the following commands, depending onobject type:

• Turn on this only – turns on the selected object and turns off all other objects• Turn off – turns off the selected object• Show contact node – highlights any nodes which are in contact with any master

object. This is a quick way to display contact. This is a toggle menu selection.Select it once to turn the contact node display on. Select it again to turn the displayback off.

• Show BCC – highlights any node with constrained velocity boundary conditions.This is also a toggle selection

• Show geometry normal vector – displays vectors normal to each surface facet.• Make transparent• Show backface – backface shows the interior or back surface of rigid objects

The Mater ial Data menu allows access to the material properties window (same windowas the preprocessor).

A meshed rigid object will contain both mesh data (for temperature calculations) andrigid surface geometry data (for contact with deforming objects). The mesh andgeometry data menus allow control of the mesh and geometry surface display.

The Mesh Data menu controls display of the object surface mesh description• Show Mesh / Hide Mesh shows or hides the display of the object surface mesh• Change shade color – changes the element fill color• Change line color – changes the color of the lines delineating element edges

The Geometry Data menu controls the display of the surface geometry description• Show Geometry / Hide Geometry shows or hides display of the surface geometry• Change shade color – changes the surface facet fill color• Change line color – changes the color of lines delineating facet edges

Additional Post Processing FunctionsWhen various post processing functions (state variables, load stroke curves, slicing, etc)are displayed, the respective icons will be added to the object tree. Right clicking onthese icons allows editing of their respective properties

Object Control BarAll right mouse menu functionality is duplicated in a control bar at the bottom of theobject tree.

Toggle object on/off (displays mesh, geometry, or both, depending on which isavailable and selected. Defaults to mesh if neither is selected)

Toggle mesh on/off

Toggle geometry on/off

Toggle item on/off – may be any item, such as slicing, a curve or graph, etc.

Display contact nodes

Toggle transparency

Toggle backfacing

Save the file, and Exit

Save the keyword file, and exit the preprocessor. We will work with a different geometryin the next lab.

Lab 3 – Bad Geometry & Geometry Repair

Depending on the CAD system used to generate STL geometry, the STL geometry maynot be a legal surface. In this lab, we will investigate geometry checking and correctionfeatures in DEFORM.

Create a new problemCreate a new problem called Crankshaft, and open the preprocessor.

Set unit systemOpen Simulation Controls and set the units to SI.

Import geometryAdd an object: “Top Die” . Import the geometry “CrankshaftDie.stl” .

Check the geometry. A clean geometry should have 1 surface and no free edges. Thisfile has 23 surfaces and 75 free edges.

Turn on the surface facet display, and visually examine the die cavity. Notice severaltangled or irregular looking facet clusters.

Display free edges

The surface patch button will display free edges in yellow, and good edges in anothercolor, depending on preprocessor settings. This can give the user an idea where the CADfile might need to be repaired. In the case of the crankshaft die, there are multiple invalidsurfaces.

Attempt repairDEFORM has a “ fix GEO” option which will attempt to repair illegal geometries bystitching open edges together. For minor or localized problems, this works well. Formore troublesome file such as this one, the repair may not produce a desirable result.

If the crankshaft surface is examined after “ fixing” geometry, several spikes and irregularsurfaces will be noticed.

It is possible, but difficult, to further edit these problem files. It is generally better toaddress the problem within the CAD software. Contact DEFORM support if this is notpossible.

Note that even thought this geometry is bad, DEFORM will generally produce results.The problems which occur will be spikes or distortions in the workpiece mesh duringforming.

ExitingClose the problem and exit the preprocessor. This file will not be used again, so it is notnecessary to save it.

Lab 4 – Mesh Generation

Open an existing problemOpen the problem “Tee”.

Generate a default meshGo to the “Mesh” screen and generate a mesh with the default number of elements(8000). Note how many elements were actually generated.

Use the measure tool to measure larger and smaller elements

Change the number of elements to 16000. Generate a mesh and measure someelements.

Change the number of elements to 32000. Repeat the measurements. Note the actualnumber of elements.

Generate mesh with absolute densityChange to the “Detailed Settings” tab on the mesh generation screen.

Change “Type” from “Relative” to “Absolute.” Set minimum element size to 0.1” andgenerate a surface mesh, then a solid mesh. Note the element size, and total number ofelements.

Change the size ratio to 1, and generate a surface mesh. Note the max and min elementsizes.

Change the size ratio to 5 and generate a mesh.

Set the minimum element size to 0.05, and generate a mesh

Set the minimum element size to 0.2 and generate a mesh.

Take some time, and experiment with different combinations of mesh size, size ratio.Note the max and min size, and total number of elements generated.

Generate a mesh for use with simulations

The final mesh we generate will be used with subsequent simulations.

Be sure mesh density is set to absolute. Set the minimum element size to 0.10” and use amaximum size ratio of 3. Generate a surface mesh, then a solid mesh.

Save and ExitSave the problem, then exit the preprocessor.

Lab 5 – Completing Pre Processing

The first operation will be a Bust operation. The billet will be positioned vertically, andupset from a height of 3.3” to a height of 1.5.”

Open existing problemOpen the problem “Tee”

Assign Material

Select Stainless Steel 316 from the material library. Assign this to the workpiece.

Assign Movement Controls

Select the top die from the object tree.

Assign a velocity of 10in/sec, and set the direction to –Z.

The “Current Die Stroke” is the distance this die has already moved. Right now, thatvalue should be set to zero.

Assign Simulation Controls

Step controlsThe first operation will be an upset. We will take the billet from 3.300” to 1.500” . Thechange in height is 1.8” . For a simple upset, 50 steps is appropriate.

Set the “Solution Steps Definition” to “With Constant Die Displacement” . Use a value of0.036 inches/step (1.8” / 50 steps).

Set the “Step increment to save” to 5.

Stopping controlsUnder the “Stop” screen, select the “Die Distance” tab.

Select the Top Die for Reference 1, and pick a point on the bottom corner of the top die.

Select the Bottom Die for Reference 2, and pick a point on the top corner of the bottomdie.

Set the measurement “Method” to “Z Distance” and enter a distance of 1.500”

Positioning the workpieceWe will perform this operation with the workpiece vertical

We will first position the workpiece on the bottom die. To make it easier to see, changeto “User Defined Object Display” mode in the control bar at the bottom of the object tree.

Then right click on the Top Die, and turn it off.

Go to object positioning, and select “ rotational” positioning. Select the workpiece.

Use the mouse to pick a point around the center of the workpiece, then select the “x” axisas the axis of rotation. Enter an angle of 90 degrees, and “Apply” . The workpiece shouldnow be vertical.

Switch to “Mouse Driven” positioning. Click on the “X” or “Y” axis and use the mouseto drag the billet to a flat spot on the die, not too close to either the forming cavity or theedge of the billet.

Use “ Interference” positioning to place the billet on the bottom die.

Right click on the Top Die to turn it back on, then use Interference Positioning to place itin contact with the billet.

Assigning interobject conditions

Select the Inter-Object Icon. You will get a message indicating that there are nointerobject relationships defined, and asking if you want to create them. Say yes.

Within the interobject window, select “Edit.” From the drop-down box next to friction“Value” select “Lubricated Hot Forming” . The system will assign a friction value of 0.3,which is appropriate for the conditions.

Close the definition window, and select the “Apply to other relations” button.

Use the “hammer” to set the contact bcc tolerance, then click “generate all.”

Generate Database

Check and Generate the database.

Save a keyword file, and close the preprocessor.

Lab 6 – Run Simulation and Postprocess

From the main window, select “Run”

The log file will indicate “end of simulation” when it is completed.

After the simulation is completed, open the database in the postprocessor.

Step selectionThe step selection list allows the user to select the steps that will be displayed during playand animation capture. Negative steps indicate remeshing or operation starting steps.

State VariablesFrom the state variable menu, plot strain. In the object tree, right click on the “strain”icon and select properties. In this screen, you can display line or shaded contours. It isalso possible to select solid shading, or element shading. Experiment with each of thesesettings.

Using “User defined global” state variable definition, the range of the contour bar can beadjusted.

SlicingUse slicing to slice the workpiece and dies. Display state variables on the sliced surface.By clicking “add” on the slicing menu, you can add multiple slicing planes.

The slider bar allows you to dynamically move the slicing plane.

Point trackingSelect point tracking. Select a few points on the object, and track the points. If a statevariable is displayed, the values of the variables will be graphed at these points.

Exit the postprocessorThere is no need to save data in the postprocessor. Just close the postprocessor

Lab 7 – Restarting Simulation

In this lab, we will open an existing file, reposition the workpiece, and run a secondoperation.

Open existing fileSelect the file Tee.DB in the main window, and open the preprocessor. Select the laststep from the database

Workpiece positioning for second operation

Reposition the billetChange to “user object display mode” in the object tree. Turn off the top die, to give abetter view of the workpiece and the bottom die.

Go to object positioning. Using Mouse positioning, drag the workpiece over the diecavity.

Now use interference positioning to be sure the workpiece is properly seated in thebottom die.

Reposition the top dieTurn the top die back on. Use interference positioning to be sure it is positioned correctlyon the billet

Reset simulation controlsFor a fast simulation of this part, we will use 100 steps. We will forge the part from aheight of 1.500 to a height of 0.250” , for a stroke of 1.250.” Set the step definition toconstant die displacement of .0125.

Reset stopping controlsWe will use stopping distance again, and stop at a flash thickness of 0.250”

Write the databaseGenerate the database. When you are writing, the system should indicate that this is an“old” database – that is – you are appending to the end of an existing file. If it were set to“New” you would be creating a new file, or erasing and overwriting an existing file.

Exit and Run the SimulationExit the preprocessor. Run the simulation. Watch the log file to indicate completion.

Postprocess the resultsAfter the simulation is completed, select the database file and open the postprocessor.

Play through the simulation. Did the part fill the die cavity? You may want to turn dieson and off, and use transparency to better visualize the part.

Right click on the workpice icon in the object tree, and display contact. Watch howcontact evolves as the part fills out

Plot the load-stroke curve. Observe how the load increases as the part fills out the dieand forms flash.

Plot the strain rate during forming. Observe what happens in the flash area.

Display the mesh on the workpiece. Measure a few elements in the radius area, and inflat areas. Does the mesh do an adequate job of resolving geometry?

Lab 8 – Simulating Temperature Effects

Create a new problemCreate a new problem called TeeNonIso

Set simulation controlsOpen simulation controls and turn on heat transfer and deformation.

Import workpieceImport the file TeeBillet.stl. Set the temperature to 2150F.

Generate meshSet an absolute density of 0.1” , and a side ratio of 3. Generate the surface and solid race.

Assign thermal boundary conditionsAssign heat exchange with the environment boundary conditions to “all surfaces” of thebillet.

Set target volumeUnder object properties, assign the target volume.

Import toolsImport the top die (TeeTop.stl). Assign a uniform object temperature of 300F.

Generate meshGenerate a mesh on the die with 15,000 elements.

Assign movement controlsAssign a constant die movement of 10 in/sec in the –Z direction

Assign boundary conditionsAssign heat exchange with the environment over the entire surface of the die.

Import bottom dieImport TeeBottom.stl. Assign a uniform object temperature of 300F.

Generate meshSet 15,000 elements with relative density, and generate a mesh on the bottom die.

Assign die materialAssign H-13 as the die material.

Assign boundary conditionsAssign heat exchange with the environment over the entire surface of the die.

Position the billetTurn off the upper die to better visualize the billet in the lower die.

Use mouse positioning to rotate and drag the billet into position.Then use drop positioning to position the billet in the bottom die.

Position the top dieUse interference positioning to position the top die against the billet.

Interobject boundary conditionsAssign default master-slave relationships between the workpiece and dies. Uselubricated hot forming friction, and assign interface heat transfer friction.

Simulation controlsWe will forge to a flash thickness of 0.250” . Measure the distance between the top andbottom die, subtract 0.250, and use this as an estimate of the forging stroke. Divide thedistance by 100, and use this for a stroke per step.

Set the stopping distance to 0.250, and set reference points on the top and bottom die.

Generate database and run the simulationGenerate a new database. Close the preprocessor and run the simulation.

PostprocessingAfter the simulation is completed, open the database in the postprocessor.

Make the dies transparent, and play through the simulation. Observe fill.

Display contact nodes, and observe the fill pattern.

Plot workpiece temperature.

Now click on the File->Open menu, and open the Tee.DB. Use the Window->Tile optionto display both databases at the same time.

By clicking in a window, the postprocessing controls influence that window. Plot load-stroke in both windows, and compare the load-stroke curves for the two windows.

Close the postprocessor.

Lab 9 – SymmetryTo demonstrate the use of symmetry, we will simulate only the top half of the Teeforging. We will also use this lab to illustrate using an existing database file as a startingpoint for a new problem.

Creating a problem and importing an existing databaseCreate a new problem called TeeSymmetry. From the preprocessor, open the databaseTeeNonIso.DB, and load the -1 step into the preprocessor.

We will make the following changes to the database:• Delete the bottom die• Import a new half-symmetry billet, and remesh it• Use appropriate boundary conditions to define symmetry• Adjust die velocity to account for symmetric movement.

Delete the bottom dieUsing the object delete button, delete object 3 (the bottom die). Because it is symmetricto the top die, it will not be used in this simulation

Import and mesh the symmetric billetSelect object 1, and go to Geometry. Do not extract geometry from current object whenprompted. Import the geometry TeeBilletSym.stl.

Go to mesh generation, and using the mesh settings already loaded from the existingdatabase, generate a new mesh on the billet.

Assign symmetry boundary conditionsFrom the boundary conditions menu, assign symmetry boundary conditions to thesymmetric face. Assign heat exchange with the environment boundary conditions to allfaces except the symmetry face.

Reassign target volumeThe billet volume has changed, so reassign the target volume

Change die velocityThe symmetry definition means that the virtual bottom die is moving upward at the samespeed that the top die is moving downward. To compensate for this, we will reduce thetop die velocity by 50%. Change it from 10 to 5 inches/second.

Reset stopping controlsSince there are no longer two objects, stopping distance cannot be used. Measure the Zdistance from the bottom of the die to the symmetry plane of the billet. Subtract 0.125(half of the flash thickness) from the total distance, and use this as the stopping stroke.

Write the database and run the simulation

PostprocessingAfter the simulation is completed, open the database in the postprocessor. Use the mirroroption, and click on the symmetry plane of the billet.Load the TeeNonIso.DB file, and compare the results. Study temperature, load-stroke,and other options.

Lab 10 – Die stressWe will run a die stress analysis on the top die from TeeNonIso.DB

Create a new problem called TeeDie

Load the final step from TeeNonIso.DB.

Delete the workpiece and bottom die.

Make the top die elastic.

Go to boundary conditions. Using the velocity boundary conditions, set the X, Y, and Zvelocity equal to zero on the top surface of the top die.

Now go to Force boundary conditions, and interpolate forces from the workpiece inTeeNonIso.DB onto the die.

Set simulation controls to 1 step at 1 second, generate the database and run thesimulation.