0. WORKSHOP 4
PIPE CRUSH ANALYSIS

2. Chapter Overview
In this exercise, a model of a cylindrical pipe is modeled as being crushed between rigid bodies.
This model is created using 2D shell elements to model the pipe, and 2D rigid surfaces above and below the pipe.
Pipe
R=4
Move 2 in the -Y
Rigid Body 2
Move 2 in the Y
R=3
Rigid Body 1

3. Objective Required Large Deflections/Strains analysis
Elastic-Plastic material model
Rigid – Deformable Contact
Required
A file named crush.bdf in your working directory (Ask your instructor for it if you don’t see it before starting)

4. Step 1. Open a New Database
Structures Workspace.
Launch SimXpert.
Select Structures.

5. Step 2. Set Unit b c a f d e Set the units to English.
Select Tools / Options
Select Units Manager.
Click Standard Units.
Select the line containing English Units (in, lb, s…)
Click OK
Click Apply. a f d e

6. Step 3. Import the crushing.bdfa
Import the required geometry.
Select File / Import / Nastran
Select crushing.bdf as the File name.
Click Apply.

7. Step 4. Delete Existing Groups and Contacts
Since we want to practice the definitions of contact bodies, we will delete existing related objects firstly
In Model Browser, right click all existing Groups and Conacts, and select Delete command to delete them one by one a

8. Step 5. Define Plastic Material
Modify the material with elastic properties.
In Model Brower, double click Material / MAT1_1_crush.bdf
Change Steel as the Material Name.
Click Advanced icon.
Click Add Constitutive Model / Elasto Plastic b c e d a

9. Step 5. Define Plastic Material (cont.)
Create the material aluminum_1100, with elastic properties.
Select Nonlinear Data Input: Perfectly Plastic.
Enter in Initial Yield Stress field
Click OK. d e e f f g

10. Step 6. LBC:Fix Pipe a b c d Select nodes to fix pipe mesh.
On LBC’s tab, select Fixed from the Constraint group
Name : fixed_end
Select nodes at the two ends of the pipe
Click OK. b c d

11. Step 7. Create contact body - Contact_mid
Create contact body for pipe mesh
On LBC’s tab, select Contact \ Deformable Body (Structural)
Enter Contact_mid as Name
Click Pick Entities field
Choose PSHELL_crush.bdf from Model Browser
Click OK b c d e

12. Step 8. Create contact body – Contact_top
Create contact body for pipe mesh
On LBC’s tab, select Contact \ Rigid Body (Structural)
Enter Contact_topas Name
Click Pick Entities field
keep only Pick Surfaces option from Pick Filters toolbar
Select the 3 surfaces as the graph below
Select Motion Tab
Switch Motion Control option to Position
Enter Position data as X=0,Y=-2,Z=0
Click OK d b c f g e h i

13. Step 9. Check contact normal - Contact_top
Open the Model Browser
Right click Contact \ Contact_top \ Properties Click Display
Click Body Tab
Click Display Inward Normals, if it’s necessary, click Reverse Inward Normals. Inward Normal should looks like the one in the following picture. k k l m d

14. Step 10. Create contact body – Contact_bottom
Create contact body for pipe mesh
On LBC’s tab, select Contact \ Rigid Body (Structural)
Enter Contact_bottom as Name
Click Pick Entities field
keep only Pick Surfaces option from Pick Filters toolbar
Select the 3 surfaces as the graph below
Select Motion Tab
Switch Motion Control option to Position
Enter Position data as X=0,Y=2,Z=0
Click OK d b c f g h i e

15. Step 11. Check contact normal-contact_bottom
Open the Model Browser
Right click Contact \ Contact_bottom \ Properties Click Display
Click Body Tab
Click Display Inward Normals, if it’s necessary, click Reverse Inward Normals. Inward Normal should looks like the one in the following picture. l k m d

16. Step 12. Create Contact Table
On LBC’s tab, select Contact \ Table
Click OK b

17. Step 13. Create the Analysis Job
Setup and launch the Analysis.
Right-click FileSet and select Create new Nastran Job.
Enter Pipe_Crush as the Job Name.
Solution Type: Implicit Nonlinear Analysis (SOL600).
Click OK a b c d

18. Step 14. Setup Analysis Parameters
Setup the Analysis Parameter
Click right mouse button, Simulation / Pipe_Crush / LoadCases / DefaultLoadCase / Properties
Select SOL600SubcaseNonlinearGeomParameter dialog
Switch Nonlinear Geometric Effects option to Large Displacement/Large Strains
Click Apply
Click Close a b c d e

19. Step 15. Select Contact Table
Right click on Simulations / Pipe_crush / Load Cases / DefaultLoadCase / Select BCTABLE
Click BCTABLE_1 from Model Browser / Contact
Click OK. b a

20. Step 16. Select Load/BCs b c a Select Load/BCs.
In Model Browser, right click Simulation / Pipe_Crush / Load Cases / DefaultLoadCase / Load/Boundaries / Select Lbc Set
Select DufaultLbcSet
Click OK.. b c a

21. Step 17. Output Requests-Element Results
Right Click on Output Requests to add the following output Displacement (1) & Total Strain Tensor (301) Plastic Strain Tensor (321) Cauchy Stress Tensor (341) a

22. Step 18. Run this job a Run this job
Open Model Browser, click right mouse button at Pipe_Crush, select Run. a

23. Step 19. Attach Results b a c Attach results files, *.t16
Select File \ Attach Results\ Result Entities…
Choose pipe_crush.marc.t16
Click OK b a c

24. Step 20. Display Results: Deformation
Display Deformation
Plot type: Deformation
Result Cases: select the last one
Result Type: Displacement,Translation
Click Update d a c b

25. Step 21. Display Results: Stress
Display Stress
Plot type: Fringe
Result Cases: select the last one
Result type: Result Type: Stress,Cauchy
Derivation: von Mises
Click Update a e d b c