WORKSHOP 4 PIPE CRUSH ANALYSIS

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

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)

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

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

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

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

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

Step 5. Define Plastic Material (cont.) Create the material aluminum_1100, with elastic properties. Select Nonlinear Data Input: Perfectly Plastic. Enter 36000 in Initial Yield Stress field Click OK. d e e f f g

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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