1. ENFORCED MOTION IN TRANSIENT ANALYSIS
WORKSHOP 7
ENFORCED MOTION IN TRANSIENT ANALYSIS
WS7-1

2. Problem Description
The purpose of this workshop is to demonstrate how to add acceleration BCs using large mass method. In this workshop, a 1x1 square aluminum plate suffers an acceleration of sin wave on the edge. The goal is to:
Add the acceleration BCs on the edge by large mass method.
Simulate the shock test.

3. Suggested Exercise Steps
Create a 1mx1m surface.
Mesh the surface.
Create MPC.
Add acceleration by large mass method.
Create the material.
Assign physical properties to the plate.
Submit the model by Single Step Houbolt (SSH) Method.
Attach the .t16 results file.
Post Process results – create a graph of the result. Check the acceleration on the edge and see the deformation of the plate and how acceleration propagates through the whole plate.

4. CREATE NEW DATABASE a Create a new database called efmotion.db.
File / New.
Enter efmotion as the file name.
Click OK.
Select MSC.Marc as the Analysis Code.
Select Structural as the Analysis Type.
efmotion d e
efmotion b c f

5. CREATE NEW DATABASE a Create a new database called efmotion.db.
File / New.
Enter efmotion as the file name.
Click OK.
Select MSC.Marc as the Analysis Code.
Select Structural as the Analysis Type.
efmotion d e
efmotion b c f

6. Step 1. Geometry: Create / Surface / XYZ
Create a geometry surface with dimension of 1m x 1m.
Geometry: Create / Surface / XYZ.
Enter <1,1,0> for the Vector Coordinate List.
Click Apply. a b c

7. Step 2. Finite Element: Create / Mesh / Surface
Create a finite element model of the surface.
Elements: Create / Mesh / Surface.
Select Quad Element Shape and IsoMesh Mesher.
Select Surface 1.
Uncheck the Automatic Calculation.
Enter 0.1 for the Global Edge Length.
Click Apply. a b c d e f

8. Step 3. Create MPC
Create the boundary condition and MPC (cont.).
Create Node: Create / Node / Edit.
Add a new node which is located at [ ].
Create MPC: Create / MPC / RBE2
Select dependent nodes (constraint 1-6 d.o.f.) on the right side of the surface (as figure shown).
Select node 129 as the independent node (as figure shown).
Click Apply. d c a e f b

9. Step 3. Create MPC (Cont.)

10. Step 4. Loads/BCs: Add force
Assign the loads to the model.
Fields: Create / Non spatial / Tabular Input
Enter acc for the New Set Name.
Check time variable.
Click on the Input Data button.
Click on the Map function to Table button.
Input sin wave function from t=0 to t=1 as figure shown.
Click Apply.
Click OK a f
acc b c g d e h i

11. Step 4. Loads/BCs: Add force (Cont.)
Assign the loads to the model (cont.).
Load Cases: Create time dependent load case first
Loads/BCs: Create / force / nodal .
Enter force for the New Set Name.
Click on Input Data.
Enter < e10> for the force.
Chose acc field.
Click OK.
Click on Select Application Region.
Change the Geometry Filter to FEM.
Select the nodes 129.
Click Add, and click OK.
Click Apply. b e
<0 0 10e10> i f j g a
force c k d h l

12. Step 4. Loads/BCs: Add force (Cont.)
Assign the loads to the model (cont.).
Loads/BCs: Create / displacement / nodal .
Enter fix_load for the New Set Name.
Click on Input Data.
Enter <0,0,> for the translations and <0,0,0> for the rotations.
Click OK
Click on Select Application Region.
Change the Geometry Filter to FEM.
Select the nodes 129.
Click Add
click OK.
Click Apply. d
node129 h i g
fix_force b e c f j k

13. Step 5. Materials: Create / Isotropic / Manual Input
Create the material.
Materials: Create / Isotropic / Manual Input.
Enter Al for the Material Name.
Click on the Input Properties button.
Enter 2e11 for Elastic Modulus and 0.33 for Poisson Ratio.
Enter 7800 for the Density.
Click OK.
Click Apply. d e b c f g

14. Step 6. Properties: Create / 2D / Shell
Assign physical properties to the plate.
Properties: Create / 2D / thin shell.
Enter plate for the Property Set Name.
Click on the Input Properties button.
Click on Material Prop Name icon, and select Al in the Material Property Set box on the bottom.
Enter for the Thickness.
Click OK.
Select Surface 1 for the application region.
Click Add.
Click Apply. a d d e b c f g h i

15. Step 6. Properties: Create / 0D / Mass
Assign physical properties to the plate.
Elements: Create / Element / Edit
Select Node 129 as 0d element
Properties: Create / 0D / Mass.
Enter mass for the Property Set Name.
Click on the Input Properties button.
Input 1e10 as Transl inertial Z.
Click OK.
Select Element 102 for the application region.
Click Add.
Click Apply. a f
1e10
mass d e h
Element 102 h b i g j

16. Step 7. Analysis: Analyze / Entire Model / Full Run
Submit the model for normal modes analysis.
Analysis: Analyze / Entire Model / Full Run.
Enter SSH for the Job Name.
Click on Job Parameter.
Check Use Tables.
Click OK.
Click on Load Step Creation.
Enter time for the Step Name.
Click on Select Load Case
Chose “time” load case. a i g b h c j f d e

17. Step 7. Analysis: Analyze / Entire Model / Full Run (Cont.)
Submit the model for normal modes analysis.
Click on Output Requests.
Click on Select nodal Results.
Chose ACCELERATION (30).
Click OK.
Click on Solution Parameters. m l p k n o

18. Step 7. Analysis: Analyze / Entire Model / Full Run (Cont.)
Submit the model for normal modes analysis.
Click on Load Increment Parameters.
Chose “Fixed” as Increment Type
Input the Parameter as figure shown.
Chose “Single Step Houbolt” as Time Integration Scheme.
Click OK.
Click Apply. r s t q u v v

19. Step 7. Analysis: Analyze / Entire Model / Full Run (Cont.)
Submit the model for normal modes analysis.
Click on Load Step Selection button.
Chose “time” job steps
Click OK.
Click on Apply. y z x aa

20. Step 8. Analysis: Access Results / Attach XDB / Result Entities
Attach the t16 result files.
Analysis: Read Reslult / Result Entities / Attach.
Click Apply. a b

21. Step 9. Results: Create / Quick Plot (cont.)
Create a Fringe plot in analysis time=3.0 sec.
Results: Create / Quick Plot.
Select the Result case Time=3.0.
Select Acceleration, Translational in Fringe Result.
Chose Z component.
Click Apply. b c d e

22. Step 9. Results: Create / Quick Plot (cont.)
Create a Deformation plot in analysis time=3.0 sec.
Results: Create / Quick Plot.
Select the Result case Time=3.0.
Select Displacement in Deformation Result.
Click Apply. b c d

23. Step 9. Results: Create / Graph / Y vs X (cont.)
Create a Graph plot through the whole analysis time.
Results: Create / Graph / Y vs. X.
Select the Whole Result cases.
Select Acceleration, Translation as Y Result.
Chose Z Component.
Select Time as X Result.
Click the second bottom on the top.
Chose the nodes as the figure shown
Click APPLY. f b g c d h e i

24. Step9. Results: Create / Graph / Y vs X (cont.)
Create a Graph plot through the whole analysis time.
Change the Y result to Displacement, translation
Click APPLY. a b