Abaqus CAE (ver. 6.12) Impact tutorial
Problem Description
An aluminum part is dropped onto a rigid surface. The objective is to investigate the stress and deformations during
the impact.
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Portland State University, Mechanical Engineering
Analysis Steps
1. Start Abaqus and choose to create a new model database
2. In the model tree double click on the “Parts” node (or right click on “parts” and select Create)
3. In the Create Part dialog box (shown above) name the part “Bracket”
a. Select “3D”
b. Select “Deformable”
c. Select “Solid”
d. Set approximate size = 200
e. Click “Continue…”
4. Create the geometry shown below (not discussed here). Dimensions are in millimeters.
a. Extrude the shape to a depth of 20.
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Portland State University, Mechanical Engineering
5. In the Create Part dialog box (shown above) name the part “Rigid”
a. Select “3D”
b. Select “Analytical rigid”
c. Set approximate size = 200
d. Click “Continue…”
6. Create the geometry shown below (not discussed here). Dimensions are in millimeters.
a. Set the extrusion depth to 200 mm.
7. Create a datum point at the center of the plate (midway between diagonal points).
8. From the menu bar select Tools  Reference Point
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Portland State University, Mechanical Engineering
a. Select the datum point just created.
b. The reference point will be created as
shown.
9. Create a surface on the rigid plate.
a. Click on the ToolsSurfaceCreate …
b. Select the rigid plate.
c. You will be prompted to pick a side for internal faces. Pick the color that is
likely candidate as the impact surface. In this example, “Brown” has been selected.
10. Double click on the “Materials” node in the model tree
a. Name the new material “Aluminum” and give it a description
b. Click on the “Mechanical” tabElasticityElastic
c. Define Young’s Modulus and the Poisson’s Ratio (use SI (mm) units)
i. Young’s modulus = 70e3, Poisson’s ratio = 0.33
d. Since this is an explicit model, material density must also be defined
e. Click on the “General” tab Density
i. Density = 2.6 e‐6
f. Click “OK”
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Portland State University, Mechanical Engineering
11. Double click on the “Sections” node in the model tree
a. Name the section “bracket_sec” and select “Solid” for the category and “Homogeneous” for the type
b. Click “Continue…”
c. Select the material created above (Aluminum) and Click “OK”
12. Expand the “Parts” node in the model tree, expand the node of the part “Bracket”, and double click on
“Section Assignments”
a. Select the entire geometry in the viewport and press “Done” in the prompt area
b. Select the section created above (bracket_sec)
c. Click “OK”
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Portland State University, Mechanical Engineering
13. Expand the “Assembly” node in the model tree and then double click on “Instances”
a. Select “Dependent” for the instance type
b. Select the parts: “Bracket “and “rigid”
c. Select “Auto‐offset from other instances”
d. Click “OK”
14. Now, rotate the bracket so that the impact will occur at the lower right corner. This will ba
accomplished by rotating the object first with respect to the z‐axis followed by rotation about x‐axis.
a. Select “Rotate Instance” icon.
b. Select the Bracket
c. Accept the default values of starting point (0,0,0) by pressing “Enter”
d. Enter (0,0,1) for the end point of rotation axis.
e. Enter ‐15 (degrees) for Angle of Rotation.
The assembly should look similar to the screen shot
below. Be sure to confirm the final rotated position
by clicking on OK at the prompt region!
15. Now, rotate the bracket about the x‐axis.
a. Select “Rotate Instance” icon.
b. Select the Bracket
c. Accept the default values of starting point (0,0,0) by pressing “Enter”
d. Enter (1,0,0) for the end point of rotation axis.
e. Enter ‐15 (degrees) for Angle of Rotation. Be sure to confirm the final rotated position by
clicking on OK at the prompt region!
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Portland State University, Mechanical Engineering
The assembly should look similar to the screen shot below.
16. In the toolbox area click on the “Translate Instance” icon
a. Select the “Bracket” geometry, click “Done”
b. Select the bottom corner of the bracket as shown.
c. Select the reference point on the”Rigid” member as the end point.
d.
Click “Ok”
e. The completed assembly should now look like is shown below.
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Portland State University, Mechanical Engineering
17. Double click on the “Steps” node in the model tree
a. Name the step, set the procedure to “General”, select “Dynamic,
Explicit”, and click “Continue…”
b. On the “Edit Step” page under the “Basic” tab, set the time
period to 0.02 seconds.
18. Double click on the “BCs” node in the model tree
a. Name the boundary condition “fix_rigid_plate” and select
“Symmetry/Antisymmetry/Encastre” for the type.
b. Select the reference point on the bracket geometry and click “Done”
c. Select “ENCASTRE” for the boundary condition and click “OK”
19. Open “Field Output Requests” node in the model tree
a. Double‐click on the “F‐Output‐1”.
b. Change the value of “Interval” to 100. This allows for
capturing of more output increments so that impact
can be better visualized.
c. You may wish to also change the “History output
Requests” to allow for better resolution of history
output plots.
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Portland State University, Mechanical Engineering
20. Select the “Create Predefined Field” icon under the Load module.
a. Name the predefined field.
b. Pulll down “Initial” step under the Step selection (see figure).
c. Set the Category to “Mechanical” and be sure “Velocity” is selected.
d. Note the prompt region asks you to select the regions.
e. Rotate the image on the screen so that the bracket can be highlighted. Be
sure the rigid plate is not selected!
f. Click “Done” in the prompt region.
g. When prompted, Enter ‐500 [mm/s] in the V2 field of the “Edit Predefined Field” window. The
velocity vectors should now be displayed on the screen.
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Portland State University, Mechanical Engineering
21. Double click on the “Interaction Properties” node in the model tree
a. Name the interaction properties and select “Contact” for the type, click “Continue…”
b. On the Mechanical tab Select “Tangential Behavior”
i. Set the friction formulation to “Penalty”
ii. Set Friction Coefficient to 0.5
c. On the Mechanical tab Select “Normal Behavior”
d. Accept defaults,
Click “OK”
22. Double click on the “Interactions” node in the model tree
a. Name the interaction, select “General Contact (Explicit)
(Explicit)” and click “Continue…”
b. Select “All* with self” on the Edit Interactions Window.
c. Be sure to assign the appropriate interaction property under
“Global Property assignment in the Contact Properties tab of
the window.
d. Change the contact interaction properties to the one created
above (if not already done)
e. Click “OK”
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Portland State University, Mechanical Engineering
23. Open the “Field Ouput‐1” and change the Interval for the output request to 100.
24. In the model tree double click on “Mesh” for the Bracket part, or use the Module section of the icon panel as
shown.
a. Select “Explicit” for element type
b. Select “Quadratic” for geometric order
c. Select “3D Stress” for family
d. Select “Tet” tab and be sure the element is C3D10M
e. Select “OK”
You may check the “Mesh Control” to be sure only TET elements
are being used in meshing.
25. In the toolbox area click on the “Seed Part” icon
a. Under “Sizing Controls” set Approximate global size to 2, Click “OK”
26. In the toolbox area click on the “Mesh Part” icon
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Portland State University, Mechanical Engineering
a. Click “Yes”
Caution: The mesh will exceed the ability of student version of the
software to solve. You need to use either Academic version or the
Research version to be able to run the job.
27. In the model tree double click on the “Job” node
a. Name the job
b. Give the job a description, click “Continue…”
c. Accept defaults, click “OK”
28. In the model tree right click on the job just created and select “Submit”
a. While Abaqus is solving the problem right click on the job submitted, and select “Monitor”
b. In the Monitor window check that there are no errors or warnings
i. If there are errors, investigate the cause(s) before resolving
ii. If there are warnings, determine if the warnings are relevant, some warnings can be safely
ignored. An example is “information” warning message below:
The option *boundary,type=displacement has been used; check status file between steps for warnings
on any jumps prescribed across the steps in displacement values of translational dof. For rotational dof
make sure that there are no such jumps. All jumps in displacements across steps are ignored
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Portland State University, Mechanical Engineering
29. In the model tree right click on the submitted and successfully completed job, and select “Results”
30.
31. To see the effect of impact, you can either animate the deformed shape, or step through each time step of
the solution. Here the step‐by‐step method is discussed.
a. In the toolbox area click on the following icons
i. “Plot Contours on Deformed Shape”
ii. Switch to the “First” step of the solution.
iii. Click on the “Next” step.
iv. Repeat a few times and observe the change in the stress contours, and
also be sure the contact does not extend into the rigid surface. You’all also notice that the
Bracket will start to separate from the rigid plate!
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Portland State University, Mechanical Engineering
32. You may also wish to see the behavior of the system energy, specifically making sure the artificial strain
energy is not a substantial percentage of the overall (Internal) energy of the system.
a. Click on the “Create XY Data” icon.
b. Be sure the “Source” is “ODB
History output” then click
“Continue…”
c. Hold the “CTRL” key and select the
energy terms you wish to plot. IN
the example
below Internal and Artifical energy
terms have
been selected.
You’ll note that Artificial Energy is a very small portion of the overall Internal Energy, thus the model
seems to be valid, at least from the standpoint of element behavior and possibility of errors due to
meshing.
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Portland State University, Mechanical Engineering