Chapter Hot Forming en(With Flash)

1 Examples hot forging

Examples hot forging

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Table of Contents1.1. Drawing Lug ............................................................................................................................... 3

1.1.1. Description of the simulation model ...................................................................................... 31.1.2. Detailed description how to simulate the process ..................................................................... 4

1.1.2.1. Analysis 1: Cooling of the billet ................................................................................ 41.1.2.2. Analysis 2: Chamfering .......................................................................................... 161.1.2.3. Analysis 3: Pre-forming .......................................................................................... 261.1.2.4. Analysis 4: Final forging ......................................................................................... 36

1.1.3. Postprocessing ................................................................................................................. 411.1.4. Final remark .................................................................................................................... 49

1.2. Support Arm .............................................................................................................................. 501.2.1. Process Description and Objective of the Simulation .............................................................. 511.2.2. Model Description and Idealization ..................................................................................... 51

1.2.2.1. First step of forge rolling of the billet ........................................................................ 511.2.2.2. How to set up the simulation ................................................................................... 541.2.2.3. Finish forging ........................................................................................................ 741.2.2.4. How to run the simulation ....................................................................................... 741.2.2.5. How to transfer the bent workpiece to the final forging step ........................................... 751.2.2.6. How to postprocess the simulation ............................................................................ 781.2.2.7. Remarks ............................................................................................................... 821.2.2.8. Conclusions .......................................................................................................... 821.2.2.9. Exercises .............................................................................................................. 831.2.2.10. Further reading and Information .............................................................................. 83

Examples hot forging Drawing Lug

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1.1. Drawing Lug

Figure 1.1. Drawing Lug

Aim of this tutorial

In this tutorial a billet is forged in a multistep process to a drawing lug (see figure above). It serves as a basic in-troduction to the use of Simufact.forming on the example of a hot closed-die forging process. Thereto the providedCAD-files are imported and defined to serve as the tool geometries. The workpiece geometry will be created withinSimufact.forming. The forming process consists from the following five process steps each simulated in an individualanalysis:

1. Cooling of the billet (transport time from oven to forging press)2. Chamfering in a prismatic tool set

3. Preforming for for material pre-distribution

4. Final forging to final geometry

Prerequisites

In order to successfully create this example you should be familiar with the basic functionalities of Simufact.forming:Please make sure, you know how to create the Objects in the object-box and are familiar with how to insert themto the process tree.

1.1.1. Description of the simulation modelThe modeling in Simufact.forming should be structured by the following five steps:

Examples hot forging Detailed description how to simulatethe process

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1. Creation and definition of a new project

2. Creation and parameterization of the properties of the individual process steps

Import of CAD-data

Definition of the material

Definition forging press

Definition of friction

Definition of thermal properties

3. Positioning of the tools and the workpiece under the consideration that the negative Z-direction the main formingdirection is.

4. Definition of the forming properties

Stroke

Output divisions for the results

5. Starting of the simulation

Model check

Start of analysis

6. Result evaluation

1.1.2. Detailed description how to simulate the process1.1.2.1. Analysis 1: Cooling of the billetCreate a new project and insert a new process. Select the application module Hot forging. The selection of the ap-plication module is determined by the forming process to be simulated in this simulation of multiple process steps,which is a hot forging process. After selecting the application module, the process type Heating has to be selected.Set the following parameters:

Simulation type3D

Solver typeFV(Finite Volume) First Order

Furnace temperature50 C

Dies: Quantity:0


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Figure 1.2. Process definition

It is important to use telling names for the individual process steps since a multi-step process is to be simulated. Thisprovides a clear and easy to understand structure of the project.

Please rename the created process to Cooling by a right mouse click on it's process name and then selecting thefunctionality Rename.

The geometry of the cold billet with the functionality Model -> Autoshape, which can be called by a right mouseclick in the object box.

Then select Rounded Cube and input the following sizes (cold geometry):

Width (X)110

Depth (Y)110

Height (Z)305

Round height

Radius8


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Unitmm

A new object is created in the Object tree.

Figure 1.3. Autoshape creation

Rename it in "Billet".

The hot geometry of the billet is determined /created by a right mouse click on the object Billet and the selection ofthe functionality Heat up. Select Cr-Mo-Steel from the presets, enter a Furnace temperature of 1250C and anInitial temperature of 25C. Use Create to create the hot geometry.


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As soon as it has been assigned to the Process tree it is visualized in the Model window.

Figure 1.4. Heat up


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Assign it to the Workpiecein the Process tree.Select the material 42CrMo4_h1 from the Material library andassign it to the workpiece of the process tree.

Figure 1.5. Model window with the geometry


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Figure 1.6. Material selection

The thermal properties of the Billet are defined next. Create a Heat object with the following properties for theWorkpiece:

Workpiece Temperature - Initial or ReheatedConstant 1250 C

Heat transfer coefficient to the environment (HTC):Constant 50 Watt/(m*K)

Emissivity for heat radiation to environment:Automatic, Surface: medium


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Figure 1.7. Thermal properties of the workpiece

Please verify, that your Process tree is equal to the Process tree shown in the following figure:

Figure 1.8. Process tree

Finally, we need to create the mesh for the workpiece. The Process tree contains a Surfacemesh object directlybelow the workpiece object. By a right mouse click on it Show/Create mesh is opened.

The Remesher slMesh, which is automatically preselected will be used to mesh the surface of the workpiece.


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Figure 1.9. Meshing properties

The built-in automatic suggests mesh sizes based on the geometry. Reduce the Element edge size to 4 mm. The Finitevolume element size of 9 mm can be left unchanged. Click on Create initial mesh to mesh the workpiece.


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Figure 1.10. Meshed workpiece

If the created mesh seams to be suitable to meet the requirements of the simulation, the mesh can be accepted byclicking on OK. Elsewise modify the mesh parameters and repeat the meshing process.

When accepting the meshing and its parameters by clicking on OK the meshing window will be closed and you areasked if these meshing parameters are to be used during the analysis run. Answer this question with Yes to create aRemesh object slMeshSur and to assign it to the workpiece.


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Figure 1.11. Remesh objectThe cooling analysis is controlled by the object Cooling which is at the bottom of the Process tree. A double clickopens the dialogue to control the properties. Please set the Total time to 10 s.


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Figure 1.12. Cooling control (FV)Flow lines on the edges can be used to analyze the position of the billet edges in the later forging process. Points arehelpful to determine the geometry of folds.

Add Flow lines on the Edges and Particles as surface Points by a right mouse click on the workpiece and selectionof the functionality Insert Flow lines -> Edges and Insert Particles -> Surface points. The automatically presetoptions can be applied without modifications.

The following figure shows the defined Flow lines (yellow) and Particles (blue).


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Figure 1.13. Flow lines and particles

The main differences between Flow lines and Particles are:

1. Particles can be used to display the simulated result values (e.g. temperature, strain) in a Time-his-tory-diagram on each of the particles.

2. "Flow lines show only the deformation and the material flow during the simulation and can be usedto check where e.g. the cutting edges of the billet will be located on the final forging geometry.

The definition of the flow lines or particles adds an entry to the process tree assigned to the workpiece in which furtherflow lines and particles can be added and the existing modified. If required, add additional flow lines and particlesas per your requirement.

The pre-processing of the heating process is accomplished and the analysis can be started by clicking on Start /

Restart . Alternatively a right mouse click on the process icon in the process tree will open a context menu whichprovides the functionality Simulation -> Start/Restart.

The dialogue Start analysis is opened. Please define where to compute the analysis: locally or on another computerin the network.


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Figure 1.14. Start analysis

1.1.2.2. Analysis 2: ChamferingIn this analysis step the workpiece imported from the process "Cooling" including its results and will be forgedbetween two dies. To setup this analysis please insert a new process with the following properties:

Application moduleHot forging

Process typeUpsetting

Simulation type3D

Solver typeFV (Finite Volume), Higher ordner

Dies: Quantity:2


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Figure 1.15. Process definition

Rename the new process to Chamfering.

Import the CAD-Data of the tools by a right mouse click in the object box, then selecting Model -> CAD previewwhich opens the File Open dialogue.


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Figure 1.16. Open

Make sure that the Unit (U) is set to millimeter(mm)and import the file chamfer.STEP. In the CAD importsettings activate the option Quality facets, then import the CAD geometries by clicking on Import. Optionally, apreview can be created with Preview which is ideal for finding optimized settings.

Figure 1.17. CAD import with quality facets

Assign the imported tool geometries to the two tools of the current process. The workpiece geometry will be taken fromthe analysis results of the process step Cooling: Make a right mouse click in the object box and select Geometry ->From result and select the process Cooling and 100% Process time. This imports the geometry and results fromthe previous process analysis including the defined flow lines and particles.


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Figure 1.18. Geometry from results

The material and thermal properties are already defined in the object box. Assign them to the current process. Toactivate remeshing during the analysis also the already existing Remesh object slMeshSur has to be assigned to theworkpiece.

As this process is a forming process we need to define a press kinematic to simulate the correct tool movements: Createa press object by a right mouse click in the object box and then selecting Press -> Manual with the following settings:

Press typeCrank press

Crank radius (R)250 mm

Rod length (L)1000 mm

Revolution30 Rpm


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Figure 1.19. Crank press

Rename the created object to Crankpress and assign it to the process Chamfering. Then assign the upper toolto the crank press so that its kinematic will be acting on the upper tool. Do also assign the Material already in theObject box to the process tree.

The tools must be assigned with the friction properties and thermal properties. Use a right mouse click in the objectbox to select Friction -> Manual to open the friction dialogue. Set the following parameters:

Specification modeAutomatic

Scaling factor for friction0.9


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Figure 1.20. Friction

These settings represent a friction condition without lubrication. Rename the created object to "no-lubrication" andassign it to both tools of the process tree.

Make a right mouse click in the object box and select Heat -> Die -> Manual and set a constant Initial die temper-ature of 150C, the other values shall remain on the preset default values.

Figure 1.21. Thermal properties of the die

Assign the object to both tools of the process tree.


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Check the process tree and make sure it is complete as shown in the following figure:


Next, the tools and the workpiece must be positioned in respect to each other.The tools have been already positionedin the CAD-system considering that the tool kinematic is acting along the Z-axis.

Rotate the workpiece by 90 around the Global X-axis by a right mouse click on the billet in the process tree andthen selecting Rotate. Subsequently align the workpiece with the function Align Bounding Box in X Center andin Y Center, in Z it's minimal Z-coordinate has to be aligned to the Max Z-coordinate of the lower die. Please makesure that ...to the box of is set to Die-2.

Figure 1.23. Align Bounding Box


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After this positioning operation the workpiece is intersecting the upper die and is not in contact to the lower die.Translate the Upper die by 100 mm in positive Z-direction, so that it is not interfering with the workpiece. Thencall the Positioner for the workpiece, save the project as asked to do so and position the workpiece along the Z-axis

with the Type Default positioner by clicking on

Figure 1.24. Positioner

Now call the Positioner for the upper die to move it in contact with the workpiece. Compare your positioning with thefollowing figure to make sure that the positioning is correct. In case the positioning went terribly wrong the positioningof the tools can be reset to the original position with the functionality Edit -> Reset Position.


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Finally, the stroke and the Sub-stages must be set: To do so, please measure the z-distance with the Measuring toolfrom the bottom edge of the upper die to the upper edge of the lower die The the stroke must be defined so that thefinal distance is 22.5 mm. Open the Forming control (FV) by double mouse click on Forming in the process treeand set the Stroke to 43.446 mm. The Direction is already predefined and does not need to be modified.


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Figure 1.25. Forming control (FV): StrokeThe defined Stroke can be visualized by an Animation to verify this setting.

Activate the additional Sub-stage Cooling and enter a Time of 3 s.


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Figure 1.26. Forming control (FV): Sub-stagesAll other settings do not require any modification. Start the analysis.

1.1.2.3. Analysis 3: Pre-formingCreate a new process by copying the process Chamfering. Rename the new process to Pre-forming. Beforeimporting the tool and workpiece geometries all geometries have to be deleted form the process. Verify that it issimilar to the following figure.


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Import the CAD file upset.STEP with Model -> CAD Preview, again using the unit Millimeter (mm) andthe option Quality facets. Assign the imported geometries to the both tools in the process tree.

The workpiece is to be imported from the previous process using 100% Process time and assigned to the workpieceof the current process.

The pre-forming process is carried out with lubrication. Therefore new friction properties have to be defined: Createa new friction object describing Medium Lubrication, like shown in the following figure. Then rename it to medi-um-lubrication and replace the no-lubrication objects of both tools by the new one in the process tree.

Figure 1.28. Friction medium-lubrication

Next, the tools and workpiece need to be positioned. The forming direction is still the negative Z-direction. Thereforethe billet needs to be rotated by 90 around the X-axis: Make a right mouse click on the workpiece in the processtree and select Rotate. Rotate the workpiece by 90 around its global X-axis. It is irrelevant if the rotation is doneForward or Backward. Then align the workpiece with Align Bounding Box... centered and above the lower die.


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Figure 1.29. Align Bounding Box

Then use the Positionierer to position the workpiece along the Z-axis and the type Default positioner, direction

to move it into contact with the lower die:

Figure 1.30. Positioner to move the workpiece in contact with the die

Align the tool Die-1 so that it is above the workpiece Billet but in contact with it.


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Figure 1.31. Aligning the upper die in contact to the workpiece

Please make sure, that the positioning looks as shown in the following figure.


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Figure 1.32. Model components after positioning

Two points need to be defined, one each on the upper and lower die. They will be used to define the stroke of thepress.Call the function Define Points in the menu Tools and define two points as shown in the following figure. Point1 is to be defined on the bottom edge of the upper tool and point 2 on the upper edge of the lower tool.


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Figure 1.33. Points

Now the missing properties are to be assigned to the process tree. Assign the already in the object box existing materialobject, thermal properties object (1250C) to the Billet. Assign the properties like in the process Chamferingto the tools. Also assign the tool kinematics described by the Press object Crankpress then submit the upper dieto this kinematics.

Double click on the mesh object and reduce the Finite volumen element size to 8 mm.

The Ambient temperature is already predefined to 50C and does not need to be modified.

Please verify if the process tree looks like in the following figure.


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Finally, the Stroke and the output divisions need to be defined: a double click the Forming icon of the process treeopens the Forming control (FV) for the definition of the Stroke.

Click on Specify stroke... to calculate the stroke with the help of the two previously defined points. For this function-ality the distance between the dies after forming must be known. Here, the Distance at 100% stroke shall be 80 mm.


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The resulting stroke is calculated and displayed. It is automatically transferred to the Forming control by clickingon OK.


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The Finite volume element size can also be controlled in the forming control and should be reduced to 8 mm.


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Use Output divisions to define 21 Equal division of Workpiece / die result steps to be provided for postprocessingduring the analysis. This is every 5% of the analysis progress.


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All other settings shall remain at their default settings.

Save the project and start the analysis.

1.1.2.4. Analysis 4: Final forgingMake a copy the process Pre-forming using Copy -> Copy without results. Following that, rename the newprocess to Final-forging.

Import the CAD geometries from the file final-forging.STEP using Model -> CAD preview. Make sure theUnit is set to millimeter (mm) and the Quality facets are used. Then delete both tool geometries from the processtree and replace them by the imported ones.

Import the geometry of the workpiece from the preceding process step including its results with the functionalityModel -> from result and selecting 100% Process time [%]. Delete the workpiece from the process tree and replaceit with the imported.

The tools and the workpiece are positioned in the same way like in the pre-forming analysis. First the workpiece hasto be positioned above the lower die cavity - attention: the workpiece has a geometry which is adopted to the lowerdie geometry and then the Positioner is used to gravity position it in the die cavity. Finally, the upper die is broughtinto contact with the workpiece, again using the Positioner.

A successful positioning will result in an alignment which is shown in the following figure.


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Figure 1.34. Model geometries after positioning

Insert also for this process two points with Define Point on the die planes facing towards the workpiece.


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Figure 1.35. Define points

If all geometries and process properties are assigned, the process tree should look like the following figure.


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Open the Forming control (FV), then click Specify stroke to calculate the stroke using the two points just definedwhich Distance at 100% stroke should be 14 mm.

Figure 1.37. Specify stroke

The calculated stroke is automatically assigned to the field Stroke:


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Figure 1.38. Forming control (FV): StrokeThe element size is the main parameter impacting the accuracy and the computing time of the analysis. A WorkpieceFV element size of 8 mm is sufficient for a rough process layout. Any more detailed analysis would require for anWorkpiece FV element size as small as 4-6 mm.

Examples hot forging Postprocessing

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Figure 1.39. Forming control (FV): Element sizeAll other parameter of the forming control do not require modifications.

Save the project and start the analysis.

1.1.3. PostprocessingThe results of the analysis are imported automatically to the GUI during the analysis run which allows to evaluatethem even during the analysis run. The presence of results is indicated in the project tree by the Resulticon .

Basic Postprocessing techniques will be explained in this chapter for the following tasks:

Evaluations of temperatures using animations and plots

Saving of animations and plots

Measuring of result values on the workpiece surface

Displaying of tool forces using diagrams

Open the result selection window by clicking on


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Figure 1.40. Result selection window

Postprocessing implies the following steps / selections to be made:

Which process analysis is to be evaluated?

All bodies of a process: select the process in the process tree

The workpiece only: select the workpiece of the process tree

One or more tools: select the tool(s) in the process tree

Result value to be evaluated: e.g. Temperature - select it by clicking on the result value in the result selection

Which Unit shall be used to determine the point of the analysis to be evaluated: Here Process time %:

For which point in time during the analysis shall the result be shown: Here 100.00 %

How shall the result value be displayed

as a result plot:

as a animation

Scalar values (e.g. tool forces) are displayed in a history plot

In this Tutorial the Temperature of the Billet after the Cooling process shall be evaluated and the temperature plotshall be saved to a file.

Select the workpiece in the process Cooling:


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Open the Result selection window with and select the Temperature:

Make sure The Process Time % and 100.00 % are selected:

Then click on to display the result plot:


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The functionalities of the Camera mode Pan, Rotate and Zoom can also be used duringresult evaluation.Position it as per your requirements and then save it using the Menu bar and selecting File -> Save

image, alternatively the Save image button can be used.

Very similarly animations are created. In this example the effective plastic strain shall be shown for the process Pre-forming in an animation.

First, select the workpiece in the process Pre-forming:


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Then select the result value, here e.g. Effective Plastic Strain:

Clicking on Animation displays the animation - please note the tools on the bottom of the animation windowto play, rewind, etc. the animation:


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The Legend can be adjusted as per user requirements - colors, ranges and many other adjustments can be done. Thesesettings are opened by the button

The button Query Result value allows to click on the surface of the workpiece and displays the nodal values ofthe selected result vale. The values at the clicked locations are displayed in a list which can be exported for furtherprocessing.


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A click on Flowlines activates the display of the defined flow lines (here shown in red) and particles (here shownin blue). The flow lines can be used to check if e.g. the edges of the billet are positioned in an critical area of the forging.


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Tool forces, among other values, are evaluated by diagrams. To display them the body or bodies to be evaluatedneed(s) to be selected in the process tree. Multiple tools (Upper and lower die) can be selected with the help of the

Ctrl-Key. A click on History plot displays the diagram. The values to be displayed are selected from the drop-down menus on the right hand of the diagram window.

Here the press forces in Z-direction are displayed as a function of the stroke:

Examples hot forging Final remark

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1.1.4. Final remarkTe aim of this tutorial example is to explain how to setup and evaluate a multi-step hot forging analysis. You areencouraged to use this example as a starting points for your own trials and experiments to become even more familiarwith the modeling of such processes. Please make sure to determine the right element sizes for your simulation needs.This can be done by a sensitivity analysis.

Examples hot forging Support Arm

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1.2. Support Arm

Figure 1.41. Process steps to manufacture support arm

Keywords

Hot bulk metal forming, 3D, multistage, Finite Element (FE), Finite Volume (FV), forge rolling, bending, upsetting,stage control, die filling, positioning, Aluminum, slMesh, Overlay Hexmesh

Educational ObjectivesThe main objective is to learn how to use Simufact.forming. This example will teach you how to set up and runa multistage forging project handing over all results between the process steps and repositioning of the workpiece.FE and FV simulations will be linked to model this process chain. Die filling will be the main attention during theevaluation of the results.

Prerequisites

Basic process understanding, Quickstart

Examples hot forging Process Description and Objective ofthe Simulation

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1.2.1. Process Description and Objective of the Simula-tionIn this 3D, finite element and finite volume simulation of a process chain, a cylindrical billet will be forged to a supportarm in a four-stage process. In order to achieve this, the provided CAD data of the tools will be read in and the tool,workpiece and process properties assigned. The process to be simulated consists of four process steps:

1. First forge rolling for distribution of the material and elongation of the billet

2. Second forge rolling for further distribution of the material

3. Bending of the billet

4. Finish forging to final shape

The aim of the simulation is to verify if the preform produced in process steps 1-3 allows for complete die filling.

1.2.2. Model Description and Idealization1.2.2.1. First step of forge rolling of the billetOne simplification of this model is the temperature distribution of the billet at the beginning of the process. It isassumed that the temperature is constant (no cooling has taken place prior to the first process stage). The thermalexpansion of the workpiece due to its elevated temperature will be considered in this model. The dies will be simplifiedas rigid dies without thermal conduction. A spring-loaded manipulator tool (here shown in yellow) will be used toguide the billet during the rolling process.

Figure 1.42. First forge rolling process step

Examples hot forging Model Description and Idealization

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1.2.2.1.1. Second step of forge rolling of the billet

The second step of the forge rolling operation will further develop the material distribution. The stage control func-tionality will be used to link this process step to the first one. Again, the dies will be simplified as rigid dies withoutheat conduction. The manipulator tool will position the workpiece at a defined initial position at the beginning of thesecond forge rolling step. During the forge rolling, again it will be used to guide the billet.

The second forge rolling process will be defined by copying the first rolling process step, adjusting its properties anddefining the take-over of the results from the first forge rolling process to the second. For an automated simulation ofboth process steps the stage control functionality will be used.

Figure 1.43. Second forge rolling process step

1.2.2.1.2. Bending to produce curved shape needed for forging process

The billet with adjusted material distribution in its longitudinal direction will be bent in an upsetting operation. Thistakes place with two rigid dies without heat conduction. The third die in the background will not be used for otherpurposes than to visually verify if the workpiece has been bent enough to fit into the die of the last process step. Youwill use the results of this simulation to determine the appropriate travel of the bending tool yourself. For this processstep, the stage control functionality will be used as well.


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Figure 1.44. Bending

1.2.2.1.3. Finish forging

Finally, the workpiece will be forged to its final shape on a crank press. The dies will be modeled in this process stepas rigid dies with heat conduction to account for the heat transfer to the dies and the subsequent temperature rise.Elasticity effects of the tools are neglected. You will select the appropriate amount of bending (stroke of the bendingprocess). You will position the workpiece with the selected bending geometry in the finish forging dies manually(assisted by the positioner).

This process step will be simulated with the FV solver, which is advantageous when flash is produced.


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Figure 1.45. Finish forging step

1.2.2.2. How to set up the simulationTo set up the simulation, start simufact.forming and create a new project.

1.2.2.2.1. First forge rolling process step

In the Process properties select Rolling from the Bulk forming processes and make sure that Hot Forging isselected and will be simulated in a 3D Simulation. Increase the number of dies to 32 (two rolling dies will beused in this process as press-driven dies and one as a static die) :


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Figure 1.46. Process properties

First, to generate a reference point we will create the manipulator and position it. To generate the model (geometry)of the manipulator, insert a model as Autoshape to the Inventory window, selecting the auto shape type Cylindershape:

Radius36 mm

Height25 mm

Angle360


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Figure 1.47. Creating the Manipulator geometry

Rename the created geometry to Manipulator.

Assign the just created model Manipulator to the Die-3 of the process tree using the drag&drop functionality:

Figure 1.48. Manipulator geometry assigned to the Process tree

Note that the name of the die assumes the name of the geometry that you insert into it.

Next, Rotate the Manipulator by 90 around the Y-axis:


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Figure 1.49. Calling the Rotate functionality

Translate the manipulator by 22 mm in positive X-direction:

Figure 1.50. Calling the Translate functionality

Insert the model (tool) geometry to the inventory window from files: lowerroller.stl and upperroller.stlare provided in the folder CAD/forge_rolling.


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Figure 1.51. Inserting the tool geometries from file

Next, you have to define the rotation axis for both roller tools by calling Rotation axis/local System... and pickingthree points (with the same radius to the desired rotation axis) on the edge of the geometry:

Figure 1.52. Defining a rotation axis

Assign the models upperroller and lowerroller displayed in the inventory window to the Die-1 and LowerDie of theprocess tree using the drag&drop functionality.


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The geometries of the tool are ready. Next you will create the workpiece geometry. Use the Model > AutoShapefunctionality in the inventory window to create a Cylinder shape with:

Radius36 mm

Height360 mm

Angle360

The created shape is the shape of the workpiece at room temperature. To compensate for its thermal expansion duringthe heating, use the Heat up... functionality with the following parameters:

Thermal Expansion CoefficientPreset of Aluminum

Furnace Temperature475 C

Initial Temperature20 C

Figure 1.53. Calling the Heat up... functionality

Drag&drop the compensated workpiece geometry onto the workpiece of the process tree, then rotate it by -90around the Y-axis. To close the gap between the workpiece and the manipulator, translate it by 172.40443 mmin negative X-direction.

Your model should now look like this:


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Figure 1.54. Intermediate state of simulation model

Activate the display of the rotation axes . Please verify if the defined rotation axes counterrotate. If they are notcounterrotating, invert the rotation axis for one of the tools in the function rotation axis/local system... using the button

. The geometry of the workpiece and the tools required for the first forming step are defined.

Next, all other process properties required for this simulation will be added to the model:

Insert the material DB.AlMgSi1_h to the inventory window from the material library and drag&drop it onto theworkpiece to insert it in the process tree. Define a press with manually assigned properties:

Press TypeTabular motion (Translation & Rotation)

Table typeTime/Velocity

Insert two entries to the table,for the process time 0 and 0.2 s each with an angular velocity of 19 radian/sec


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Figure 1.55. Press properties

Verify the correct rotation direction of the defined press by starting the press animation .

Depending on the direction of the local coordinate systems defining the rotation axis of the tools, it might be necessaryto change the rotation direction of the press by defining a negative angular velocity.

The next properties to be defined are the friction properties of the tools. Select a manual definition:

Type of frictionPlastic shear friction

Interface friction factor0.7


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Figure 1.56. Friction properties

Assign these friction properties to both tools at once by dropping the friction onto the process in the process tree.Define the thermal properties for the upper and lower dies as follows and drag&drop them on the upper and lower die:


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Figure 1.57. Thermal properties of the upper and lower die

For the manipulator, define the following thermal properties and drag&drop them onto the manipulator:

Figure 1.58. Thermal properties of the manipulator

Define the thermal properties of the workpiece and assign them by drag&drop to the workpiece:


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Figure 1.59. Thermal properties of the workpiece

The workpiece geometry requires to be meshed. To do so, select Show/create mesh... by a right mouse click on themesh assigned to the workpiece in the process tree and create a mesh with the following properties:

Element size5 mm

MesherOverlay Hex

When leaving the mesh functionality, confirm to use the initial mesh parameters for remeshing.


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Figure 1.60. Meshing the workpiece

A spring will be used to define the movement of the manipulator and to move the workpiece back to its originalposition after the first forge rolling process. Insert a spring to the inventory window (Die type > die spring > Manual)with the following properties and drag&drop the spring onto the manipulator:

Initial conditionThe spring is released

DirectionX

Displacement500 mm

Fixed Stiffness10 N/mm

Fixed initial force0 kN


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Figure 1.61. Spring properties for the manipulator

To prevent a detaching between the manipulator and the workpiece, a "glued contact" must be defined. Insert an FEcontact table by a right mouse click on the process in the process tree:

Figure 1.62. Inserting an FE contact table

Activate the contact between the workpiece and the manipulator setting the following properties, leaving the otherproperties unchanged:

DirectionFirst to second

Contact typeGlued


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Figure 1.63. Contact properties between Workpiece and Manipulator

Finally, adjust the Forming properties: Activate the checkbox to position dies attached to the press:


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Figure 1.64. Adjusting forming controlSet the following properties for the Step Control:

ModeFixed time steps

Fixed Number of time steps270


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Figure 1.65. Step control

1.2.2.2.2. Second forge rolling process step

Copy the first forge rolling process without results:


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Figure 1.66. Copying a process without results

After copying, the process tree will show both processes. For better orientation, you should rename both processesto e.g. Forgerolling1 and Forgerolling2:


For the second forge rolling process, the second cavities of the forge rolling tools will be used. Adjust the position ofthe manipulator tool by translating it by -120 mm in Y-direction:


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Figure 1.68. Translating the manipulator

To continue the simulation with the workpiece already formed in the first forge rolling step, insert the stage controlby a right mouse click on processes to the process tree:

Figure 1.69. Inserting a stage control

Then drag&drop both forge rolling processes onto the stage control to submit both process steps to the stage control:

Figure 1.70. Process steps submitted to the stage control

Open the properties of the second forge rolling process step submitted to the stage control by a right mouse click:

Figure 1.71. Accessing stage control properties

Select the workpiece and edit its properties to rotate it by 90 around the X-axis and to translate it by -120 mmalong the Y-axis:


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Figure 1.72. Parameters for workpiece imported from first process step

1.2.2.2.3. Bending

Prepare the simulation model for the bending process on your own according to the following information - only stepswhich have not yet been carried out in the previous process steps are explained in detail:

Insert an upsetting process (3D, hot forging, 1 press driven die, 2 regular dies)

Import tool geometries using the CAD import functionality from the folder CAD/bending. The T-shaped tool willbe press-driven, the V-shaped will be the stationary die.

Rename the workpiece to workpiece-T475.

Translate the upper die by -20 mm along the Z-axis.

Import the tool geometry of the lower die of the finish forging process (file ff-lowerdie.igs) using the modelfrom file functionality from the folder CAD/finish_forging and rotate the geometry by 90 around the X-axis,translate by 100 mm along the Y-axis, then rotate by 14 around the Y-axis and finally move by 20 mm along theZ-axis until the final forging die is placed behind the bending tools and the position of the workpiece, the bendingdies and the forging dies are aligned:


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Figure 1.73. Final forging die aligned behind bending dies

Assign the already defined workpiece material properties to the workpiece

The upper die is moved by a Crank press with a crank radius of 250 mm, a rod length of 1000 mm and workingwith 30 rotations/min.

Assign Coulomb friction with a static friction coefficient of 0.2 to the dies

The dies have an initial temperature of 200 C, a heat transfer coefficient to the environment of 50 Watt/(m2*K)and to the workpiece of 20000 Watt/(m2*K). The emissivity for heat radiation to the environment is 0.25.

The workpiece thermal properties are the same as in the previous process steps and can be assigned to the workpiece.

Also, the remeshing options already defined in the previous steps can be assigned to the workpiece.

Assign all geometries and properties to the process tree.

Use the forming control to define the stroke as 0 mm. Setting the stroke to 0 mm in combination with activatingthe automatic positioning of the dies attached to the press will result in an automatic calculation of the stroke. Thestroke will be the distance between the position of the die after the positioning and the given position of the upperdie, which is regarded as its final position.

Use the forming control to make sure the sub-stages from 1 to 5 will be simulated and that 31 output divisionswill be used.

Add the bending process to the stage control.

Define the following translation to be done by the stage control:


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X275 mm

Y120 mm

Z30 mm

1.2.2.3. Finish forgingInsert another process to the process tree of type: Forming without flash.

Import (using the CAD import functionality) the tool geometry of the upper die from the folder: CAD/finish_forging(the tool geometry of the lower die is already in the inventory window) and assign both tool geometries to the dies.

Translate the upper die by 60 mm in positive Z-direction.

Assign the friction and thermal properties already used in the bending process to the tools.

Also assign the crank press already used in the bending process to the process tree and subject the upper die tothe press.

You have to assign the material properties and the thermal properties already used in the previous process stepsto the workpiece.

Define the following settings in the Forming control:

Stroke60 mm

Element size5 mm for both, workpiece FV and die FV

Output divisions51 equal division for workpiece / die and Finite volume

Advanced / SolverStandard Solver should be deactivated

Deactivating the "Standard Solver" activates the "Higher Order Solver", which is more accurateand will become the new default solver in the near future.

1.2.2.4. How to run the simulationStart the simulation for the first three process steps by a right mouse click on the stage control functionality:

Figure 1.74. Starting a stage-controlled simulation

During a simulation using a stage control, the project must not be closed or the Simufact.forming GUIexited. This would abort the running simulation.


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The stage control will indicate that the simulation is finished by green color:

Figure 1.75. Stage control indicating completed simulations

Please refer to the Reference Manual for an explanation of all colors indicating the conditions of the simulationscontrolled by the stage control.

1.2.2.5. How to transfer the bent workpiece to the final forging stepDisplay the simulated shape of the workpiece in the bending process step by means of an animation:

Figure 1.76. Simulated geometry during the Bending process step

Determine visually the process time percentage (%) at which the bent workpiece seems to fit best to the geometry ofthe die to be used for the finish forging process step. Insert the model From result... using the process time as justdetermined to the Inventory window:


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Figure 1.77. Inserting a model from results

Figure 1.78. Selecting the step to be used for further simulation

Drag&drop the workpiece just created from the results to the workpiece in the process tree of the finish forgingprocess.

The workpiece needs to become positioned to fit into the lower die: Use the manual positioning functions accessibleby the mouse tool bar to rotate and move the workpiece as close as possible to a preliminary position just above thedie (without interfering with the die!):


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Figure 1.79. Preliminary position of the workpiece in the finish forging die

Then call the positioner to position the workpiece to its final position touching the die:


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Figure 1.80. Calling the Positioner

Figure 1.81. Positioning the workpiece in contact to the die

Save the simulation model and start the simulation of the finish forging process step using the start button .

1.2.2.6. How to postprocess the simulationDuring the simulation intermediate simulation results are automatically imported to the GUI. Once the simulationof the finish forging process step has completed, all computed results are available within the GUI. This exemplarypostprocessing will focus on the most important results the user might be interested in when performing such a typeof simulation.

An effective method to visualize multiple results at once is the following method:

Open the result selection bar by clicking on the button


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Activate the FinishForging process in the process tree window by a left mouse click.

Select the workpiece only by a left mouse click.

Select 100.00 % from the context menu.

Activate the checkboxes of the results to be displayed in the result selection bar:

Effective plastic strain

Temperature

Die contact

Figure 1.82. Selecting the results to be displayed

Open the result animation by a right mouse click on the last checked item and selecting to display the checked items:

Figure 1.83. Displaying multiple results at once

This will open three windows with the selected simulation results. Use Window > Tile from the menu to arrange thedisplayed result windows:


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Figure 1.84. Tiled result windows

Use the play, pause, stop and backward/forward buttons to view the displayed result for different time steps. Moveand rotate the displayed workpieces using the mouse or the SpaceDevice.

Representative of all the other results, the die contact is very good for the entire extent of the cavity and excellent diefilling can be expected for this process:


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Figure 1.85. Simulated die contact (die filling)To display the simulated upsetting forces, click on the FinishForging process in the process tree, then click the history

plot button :


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Figure 1.86. Simulated history plot of forces

Use the checkboxes in the selection to choose the die forces to be displayed. The values and their units can be changedfor each axis individually.

1.2.2.7. RemarksTo reduce computing times, especially if many variants need to be simulated to determine the correct workpieceposition in the forging dies, the Standard Finite-Volume solver may be used. For validation of the results the user maywant to repeat the simulation with the best position using the Higher Order Finite-Volume solver, which generallyleads to higher accuracy at the expense of higher computing time.

1.2.2.8. ConclusionsThis example demonstrates a process chain simulation using the Finite Element and Finite Volume solver. The processsteps have been linked transferring the simulated workpiece geometry and properties to subsequent process steps. Thelinkage was carried out by both available possibilities - manually and using the stage control functionality.


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1.2.2.9. Exercises1.2.2.9.1. Aim of the exercises

If the simulation shows incomplete die filling, repeat the simulation of the final forging step with a different positionof the bent workpiece in the finish forging die. Second, select a workpiece from the bending process step which wasbent more or less than the one already simulated.

This exercise will give you the opportunity to further practice working with Simufact.forming.

1.2.2.9.2. PostprocessingRepeat the postprocessing steps as described above. Compare the die filling and the upsetting forces.

Were you successful to achieve complete die filling?

1.2.2.10. Further reading and InformationPlease find a similar process model in the Examples section.

Chapter1.Examples hot forgingTable of Contents1.1.Drawing Lug1.1.1.Description of the simulation model1.1.2.Detailed description how to simulate the process1.1.2.1.Analysis 1: Cooling of the billet1.1.2.2.Analysis 2: Chamfering1.1.2.3.Analysis 3: Pre-forming1.1.2.4.Analysis 4: Final forging

1.1.3.Postprocessing1.1.4.Final remark

1.2.Support Arm1.2.1.Process Description and Objective of the Simulation1.2.2.Model Description and Idealization1.2.2.1.First step of forge rolling of the billet1.2.2.1.1.Second step of forge rolling of the billet1.2.2.1.2.Bending to produce curved shape needed for forging process1.2.2.1.3.Finish forging

1.2.2.2.How to set up the simulation1.2.2.2.1.First forge rolling process step1.2.2.2.2.Second forge rolling process step1.2.2.2.3.Bending

1.2.2.3.Finish forging1.2.2.4.How to run the simulation1.2.2.5.How to transfer the bent workpiece to the final forging step1.2.2.6.How to postprocess the simulation1.2.2.7.Remarks1.2.2.8.Conclusions1.2.2.9.Exercises1.2.2.9.1.Aim of the exercises1.2.2.9.2.Postprocessing

1.2.2.10.Further reading and Information

Chapter Hot Forming en(With Flash)

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