stress analysis using deform 3d
DESCRIPTION
stress analysis in a ring under various loading and friction condtionsTRANSCRIPT
4. SQUARE RING
4.1. Introduction
4.2. Creating a New Problem
4.3. Creating New Objects
4.4. Meshing the Billet
4.5. Setting Boundary Conditions
4.6. Inter-Object Relationships
4.7. Finishing Setup and Running Simulation
4.8. Post Processing
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4. SQUARE RING
4.1. Introduction
Symmetry should be taken advantage of whenever possible in simulations. Doing so savescomputational time and can increase solution accuracy. Furthermore, the smallest possible sectionthat adequately describes the problem should be modeled.
In this lab, we will simulate the upsetting of a square ring. The square ring has quite a bit ofsymmetry that can be taken advantage of. This lab will show you that the deformation of the entirering can be determined by only modeling 1/16 of its full geometry.
4.2. Creating a New Problem
On a unix machine, type DEFORM3 to open DEFORM™-3D. On a Windows machine, go to the
button and select DEFORM-3D from the menu. The DEFORM-3D MAIN window will
appear.
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Create a new problem by clicking the New Problem icon. Accept the default setting of
opening a new problem using the DEFORM-3D pre-processor by clicking . Click
to define the location of the new problem 'Under problem home directory'.
In the field for Problem Name, call the problem SquareRing and click . The
DEFORM-3D Pre-processor will open.
4.3. Creating New Objects
To simulate the forging of this square ring, only a workpiece and a top die are required - the
bottom die is not needed due to symmetry. If Object 1 does not exist, click twice to add Objects
1 and 2. If Object 1 does exist, click once to add Object 2.
Highlight Object 1 in the Object Tree. Click on the button and change the Object Name
to Billet and the Object Type to Plastic. Define the billet's geometry by clicking and
then . The geometry is located in the file SquareRing_Billet.STL in the
DEFORM3D\V6_1\Labs directory. . Use the and buttons tocheck the geometry.
Highlight Object 2 in the Object Tree. Click on the button and change the Object Name
to Top Die. Click and import the file SquareRing_TopDie.STL in the
DEFORM3D\V6_1\Labs directory. . Use the and buttons to
check the geometry. View Fit can be used to fit both objects in the DISPLAY window.
4.4. Meshing the Billet
Highlight the Billet in the Object Tree, and then click the button to bring up the Meshing
Controls. Click on the button to see what the surface mesh looks like when using
the default mesh settings. The surface mesh that is created looks good, so click the
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button to finish the meshing process. When the meshing is complete, the object should have around
5000 elements.
4.5. Setting Symmetry Boundary Conditions
Symmetry is being taken advantage of in this simulation and only 1/16 of the square ring is being
modeled. Boundary conditions have to be used on all of the symmetry planes to enforce the correct
deformation.
Click on the button to look at the Boundary Condition options. Select the Symmetry
plane option and then select the surface that is normal to the X-axis (shown below). The nodes on
the surface will get highlighted, and the Plane Information will be listed in the Boundary Condition
area.
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Click the button to add these boundary conditions. This symmetry plane will now be
listed in the BCC list as (1,0,0) which is the normal to the plane.
Add the boundary conditions for the other two symmetry planes in the same manner. First select
the planes so that the nodes get highlighted and then use the button to add them. When
all three symmetry planes have been added, the Boundary Condition area should look like the
following:
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4.6. Inter-Object Relationships
The relationship between the Billet and the Top Die needs to be defined. Click the icon to
open the INTER-OBJECT window. When asked whether you want to add the default inter-object
relationships, click .
Define the friction for the relationship by clicking the button. Use the pull-down
menu to select the friction suitable for Cold forming (steel dies).
Back in the INTER-OBJECT window, use the icon to determine a suitable contact tolerance
(a value of about 0.002" will be calculated) and then click the button to generate
contact. If you rotate the objects around, you will see that contact was generated between the two
objects. Click to exit the INTER-OBJECT window.
4.7. Finishing Setup and Running Simulation
To finish the problem setup, the following still needs to be done:
1) Highlight the Top Die in the Object Tree and then click the button. Define a speed
of 1 in/sec in the -Z direction.
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2) Click the icon in the General page, to define a material for the Billet. Select the material
'AISI-1045, COLD' from the Steel Category. Assign this material to the Billet.
3) Click the icon to open the SIMULATION CONTROL window. Change the Simulation
Title to Square Ring. Click the button and set the Number of Simulation Steps to
30 and set the Step Increment to Save to 2. Set the Primary Die to Top Die.
To determine an appropriate step size, select the icon and measure the edge length of a few
of the smaller elements in the Billet. An average length of a short edge is around 0.06”. Use a
Constant Die Displacement per step of 0.02 in/step, which is 1/3 of this small edge length.
Click to close the SIMULATION CONTROL window.
Save a keyword file for the problem by clicking the button.
Click the icon to open the DATABASE GENERATION window. Click to
check the problem. The only should deal with Volume Compensation - ignore this for this lab.
Generate a database by clicking .
Once the database has been generated, the DATABASE GENERATION window,
and then use to return to the MAIN window. Start the simulation by clicking in the
list.
Monitor the progress of the simulation by looking at the Message file, making sure that the
option is checked.
4.8. Post Processing
When the simulation is complete, review the results by clicking the button.
In reality this part is a full square ring, so it would be useful to be able to view the entire part in the
Post-processor. To create the entire object, the small 1/16 section has to be mirrored about the
symmetry planes. Clicking the icon opens the SYMMETRY DEFINITION window.
Use the mouse to click on the symmetry planes on the Billet. Each time this is done a mirror image
of the billet will be displayed. Repeat the process until the entire billet is shown. This procedure is
illustrated below.
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Once the complete part is displayed in the DISPLAY window, close the SYMMETRY
DEFINITION window. Play through the steps to observe how the square ring deforms as it is
compressed. Experiment with viewing the different state variables such as effective strain.
When finished viewing the results of the simulation, use the icon to return to the MAIN
window. When you are back in the MAIN window, exit DEFORM-3D by selecting .