HX-0201: Tool Deflection Analysis

The purpose of this tutorial is to show how to perform tool deflection analysis to understand how the die will deform under the stresses of the material flow. When the billet, pushed by the ram stem (via dummy block) deforms and flows through the die, it exerts enormous forces on the die walls and causes it to deflect. These deflections may be large enough to produce parts of poor quality and sometimes even break the die. HyperXtrude is used to predict the tool deformation and tool stresses caused by the flow stresses. The stresses computed on the workpiece, as it deforms, is used to determine the load on the tool at the interface between the tool and the workpiece. In addition to this, HyperXtrude also considers the thermal load arising largely out of frictional heating. Using this data, tool deformation and tool stresses are computed, which is used to assess the quality of the die, understand the underlying problems, and correct it.

Files

This exercise uses the model file HX_0201.hm.

The model files for this tutorial are located in the file mfs-1.zip in the subdirectory \hx\MetalExtrusion\HX_0201. See Accessing Model Files.

To work on this tutorial, it is recommended that you copy this folder to your local hard drive where you store your HyperXtrude data, for example, “C:\Users\HyperXtrude\” on a Windows machine. This will enable you to edit and modify these files without affecting the original data. In addition, it is best to keep the data on a local disk attached to the machine to improve the I/O performance of the software.

1.	Select Start Menu > All Programs > Altair HyperWorks > Manufacturing Solutions > HyperXtrude to launch the HyperXtrude user interface. The User Profiles dialog appears with Manufacturing Solutions as the default application.

2.	Select HyperXtrude and Metal Extrusion.

Click OK.

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1.	From the File menu, select Open....

2.	Browse to the file HX_0201.hm and click Open.

This model contains the finite element mesh that contains the workpiece and the tool (container and die).

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After you load an .hm file or import a HyperXtrude deck, you need to check/set the units used. To check/set the units used, perform the following steps:

1.	On the Import Data section of the Utility Menu, click Select Units. The Select Model Units dialog displays.

2.	Set the Unit System to British and click OK.

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1.	On the Utility Menu, click Material Database. The Select and Assign Material from Database dialog displays.

2.	Expand Workpiece, then expand Aluminum_Alloys and expand 6000_Series.

3.	Select AA6063 and click Add-> to add the material under Selected Materials.

You do not need to assign a material in the Extrusion Wizard. The selected material will be assigned to the workpiece automatically.

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4.	Expand the Tool_Material directory.

5.	Expand the Tool_Steel directory.

6.	Select H_13 and click Add.

Note: In this tutorial, the Extrusion Wizard is not used. So, material must be explicitly assigned to the relevant components. You do not need to assign a material in the Extrusion Wizard. The selected material will be assigned to the workpiece automatically.

7.	Under Selected material, highlight the AA6063 material and right-click.

8.	Select Assign Material. A window displays to assign AA6063 material properties to elements in each component collector.

9.	Select the Billet3D, Pocket13D, Bearing3D and Profile3D check boxes to assign AA6063 material properties.

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10.	Click Update.

11.	Now right-click on H_13 and select Assign Material.

12.	Select the components Die3D and Container3D. The Tool material requires input for Deformation Type.

•	For Die3D - set the deformation type to Stationary_Elastic

•	For Container3D - set the deformation type to Stationary_Rigid

It is important to set at least one tool component as StationaryElastic. The term StationaryElastic means that the component does not move and it can undergo elastic deformation. If the material is rigid, then it does not undergo deformation and can undergo only rigid body motion.

If your model already has the material assigned, use this procedure to inspect the data.

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13.	Click Update.

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14.	Review the material property by double-clicking the material name under Selected materials.

Note: Understanding material property is important. For example, if an analysis results in a higher temperature than melting point, it could indicate problems, such as a tool ram speed that is too fast and must be slowed down.

15.	Click Close to close the dialog.

1.	On the Boundary Conditions section of the Utility Menu, click Create/Edit BC.

2.	The Create/Edit Altair HyperXtrude Boundary Conditions dialog opens. Click BCs to create a new boundary condition.

3.	On the right side of the panel you will see the current boundary condition. Edit this panel to set the following conditions.

•	Name = BilletDummyBlock

•	Type = Inflow

•	Material: Leave the default as it is

4.	Select a color of your choice for the BC.

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5.	Click Create to set the parameters for this BC. Set the following data and leave the rest to default values.

•	Z-Velocity =15 ipm

•	Temperature = 800.0 deg F

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6.	Click Update to save this data.

Note: For the BilletDummyBlock BC (inflow), your extrusion velocity (Z velocity in this example) will have to be identical to your Process data - Parameters - Metal Extrusion - Ram Speed. You will evaluate process data later in this tutorial.

In the following steps, you will assign elements into the dummy_block boundary condition you just created.

7.	Click the XY Bottom Plane View icon on the toolbar to change the graphics view.

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8.	Click Create Faces to prepare assigning BC face elements for this BC.

9.	With the blue halo surrounding the elem button, select the boundary elements by selecting one of the interior elements on the Inflow face with the left mouse button.

10.	Click proceed to create BC faces and assign it to this BC.

11.	When you are finished, notice that the BilletDummyBlock regions are identified and face elements are created and assigned to the BilletDummyBlock_BC.

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12.	Click on the Model Browser and notice a new component, DummyBlock_BC, is created.

13.	Next, you will create the BilletContainer BC. This BC represents the Billet surface that is in contact with the Container. Click on BCs in the Create/Edit Altair HyperXtrude Boundary Conditions window.

14.	Set the Name of the BC as BilletContainer; Type as SolidFluidInterface and accept the default material (Workpiece material). Choose a color and click Create.

15.	Under Edit BilletContainer (SolidFluidInterface) boundary conditions:, accept the default values for the Friction model and XVelocity, YVelocity, ZVelocity and Strain.

16.	Select Mismatched for Contact type.

17.	Set the value of 528 for Heat transfer coeff. You will set the Contact surface little later.

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18.	Click Update and click on Create Faces.

19.	Display only the Billet in the graphics area. Select an element on the Billet surface as shown in the figure below.

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20.	Click on elems >> by face and click proceed. This will create the face elements for BilletContainer BC.

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21.	Similarly, create the ContainerBillet BC with the attributes

Name: ContainerBillet

Type: SolidFluidInterface

Material: H_13(Tool)

22.	Choose a color and click Create.

23.	Under Edit BilletContainer (SolidFluidInterface) boundary conditions:, accept the default values for the Friction model and XVelocity, YVelocity, ZVelocity and Strain.

24.	Select Mismatched for Contact type and set the value of 528 for Heat transfer coeff:.

25.	Set the Contact surface to BilletContainer from the dropdown menu.

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26.	Click Update and click on Create Faces.

27.	Display only the Container in the graphics area. Select an element on the Container inner surface as shown in the figure below. This will create the face elements for ContainerBillet BC.

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28.	Click on elems >> by face and click proceed.

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29.	Now click on the BilletContainer under BCs and set the Contact surface as the ContainerBillet using the drop down menu.

30.	Similarly create all other BCs with attributes and the data as detailed below

Note:

If the Contact Surface required for the BC data is not available under the Contact Surface drop down, you have not yet created it. Work through the table in the order provided, going back and adding the Contact Surfaces as you create them.

Region	BC name	BC Type	BC Data
Billet - Die Contact Surface on the Billet	BilletDie	SolidFluidInterface	Friction = Stick X, Y, Z Velocity = 0 Contact Type = Mismatched Contact Surface = DieBillet Heat Transfer Coeff = 528 Strain = Unspecified
Billet - Die Contact Surface on the Die	DieBillet	SolidFluidInterface	Friction = Stick X, Y, Z Velocity = 0 Contact Type = Mismatched Contact Surface = BilletDie Heat Transfer Coeff = 528 Strain = Unspecified
Pocket1 - Die Contact Surface on Pocket1	Pocket1Die	SolidFluidInterface	Friction = Stick X, Y, Z Velocity = 0 Contact Type = Mismatched Contact Surface = DiePocket1 Heat Transfer Coeff = 528 Strain = Unspecified
Pocket1 - Die Contact Surface on the Die	DiePocket1	SolidFluidInterface	Friction = Stick X, Y, Z Velocity = 0 Contact Type = Mismatched Contact Surface = Pocket1Die Heat Transfer Coeff = 528 Strain = Unspecified
Bearing - Die contact surface on the bearing (extracted from “Bearing3D component” )	BearingDie	SolidFluidInterface	Friction model = Viscoplastic Friction coeff = 0.3 Slip Velocity X, Y, Z = 0 Contact Type = Mismatched Contact Surface = DieBearing Heat Transfer Coeff = 528 Strain = Unspecified
Bearing - Die contact surface on the Die (extracted from “Die3D component” )	DieBearing	SolidFluidInterface	Friction model = Viscoplastic Friction coeff = 0.3 Slip Velocity X, Y, Z = 0 Contact Type = Mismatched Contact Surface = BearingDie Heat Transfer Coeff = 528 Strain = Unspecified
Profile Surface	FreeSurface	FreeSurface	Heat transfer type = Heat Flux Heat flux = 0
Profile Exit	Exit	Outflow	X, Y, Z Traction = 0 HeatFlux = 0 Pressure is checked and 0
Container Outer Diameter	ContainerOD	ToolSurface	X, Y, Z displacement = 0 Heat Transfer type = Heat flux Heat flux = 0
Die Outer Diameter	DieOD	ToolSurface	X, Y, Z displacement = 0 Heat Transfer type = Heat flux Heat flux = 0
Die exposed region (with Radius > 4) facing + Z direction	DieFixed	ToolSurface	X, Y, Z displacement = 0 Heat Transfer type = Heat flux Heat flux = 0
Die remaining	DieFree	ToolSurface	X, Y, Z traction = 0 Heat Transfer type = Heat flux HeatFlux = 0
Container Back	ContainerBack	ToolSurface	X, Y, Z displacement = 0 Heat Transfer type = Heat flux Heat flux = 0

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Note:

a)	If you are in doubt about any of the BCs, look at the completed model at the same location.

b)	Mismatch interface indicates the common boundaries between Tool and Workpiece are different.

c)	Nodes are not equivalenced between two different mismatched interfaces.

d)	Mismatched interface can be used for both Steady State and Transient analysis.

e)	You must specify boundary conditions over elements on both sides of the contact surfaces (Two BC components).

f)	When ToolSurface specified with X,Y,Z displacement = 0, you are defining that the associated tool location is fixed. When X, Y, Z traction = 0 is specified, you allow the Tool to freely move.

g)	You can also use Face panel to extract 2D face elements from solid elements, then assign to different boundary BC component individually.

h)	In this tutorial, the BC attributes are the same in both DieOD and DieFixed BC components. An alternative method is to combine both BC components and create only one BC component.

SolidFluid interface enables materials to slip. This BC type has multiple slip models, such as coulomb friction, slip velocity, etc. When the SolidFluid interface is set, heat transfer is applied. If meshes are joined, the solver calculates the heat transfer automatically. If not, the heat transfer needs to be manually specified and the heat transfer coefficient is defined by the user.

Next you will define the process parameters. The process parameters allow you to control the run by specifying the equations/physics to be solved, define control parameters such as convergence tolerances, number of iterations/time steps, etc.

1.	On the Process Data section of the Utility Menu, click Parameters. The Define Altair HyperXtrude Analysis Parameters dialog displays.

2.	On the Session tab, set the following conditions:

Process Type: = Metal_Extrusion

Job Name: = HX_0201_FINAL

Job Description = Tool Deflection Analysis

Leave the remaining parameters as default values.

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3.	Click the Metal Extrusion tab and in that page set the following data:

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4.	Click Update and close the window.

If the default values shown for some of the parameters are not the same as shown above and if you can’t have access to update them, temporarily change Analysis Type: to TransientFixedBoundary or TransientMovingBoundary and set the parameters. Once the parameters are changed as required, change Analysis Type: back to SteadyState.

Note:

•	Container Diameter = Container Inner Diameter = Billet Outer Diameter)

•	Ram Speed value and the extrusion velocity for inflow BC (BilletDummyblock_BC) should be the same.

•	Calculate Tool Deflection = Yes

When Calculate Tool Deflection = Yes, HyperXtrude computes the tool deflection due to surface forces and thermal loads.

•	Mesh Update Flag = On

When Mesh Update is on, mesh nodal coordinate is updated due to computed displacements and mesh is moved to adhere to the deformed shape.

1.	Click the Model Browser.

2.	Right click on Component and select Show. This ensures all components are displayed.

3.	In the Boundary Conditions section of the Utility Menu, click Check Undefined BC. The Success: No undefined BCs dialog window should appear.

Click OK.

This ensures all the boundary faces of the displayed elements have BC faces defined on them.

5.	In the Boundary Conditions section of the Utility Menu, click Check Duplicated BC. The Success: No duplicate BCs dialog window should appear.

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Click OK.

This ensures no duplicate BCs are created.

7.	Click File > Save As and save the file as HX_0201_FINAL.

1.	In the Utility Menu, under Export Data:, click Launch Solver. This starts the HyperXtrude analysis.

2.	Enter the project file name: as HX_0201_FINAL.

3.	Set Model type = Three-Dimensional and Launch solver = Interactive.

4.	Click Launch.

The Altair HyperXtrude interactive window is launched. The Ready (displayed in green) button will turn red indicating that the code is ready for solving the solution.

Observe the run diagnostics on the screen and wait till the Ready button turns green again.

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5.	Click the Solve panel within the Altair HyperXtrude interactive window.

6.	Post-process the results using HyperView.

Note:

If tool deflections are zero, check if the SolidFluid interfaces are properly applied on the tool elements at the tool workpiece contact surfaces. When the contact surfaces are not defined properly, the HyperXtrude solver does not transfer extrusion loads from the workpiece elements (billet). Hence, surface tractions at the contact are outputted as zero.

Return to Metal Extrusion Tutorials

HX-0201: Tool Deflection Analysis

HX-0201: Tool Deflection Analysis

HX-0201: Tool Deflection Analysis

Files

Region

BC name

BC Type

BC Data

Note: