1. REFERENCE: Training Manual Friction (4-18) Planar Seal (part 2) Workshop 2 Contact with Friction Constant Friction Coefficient

2. Workshop Supplement October 15, 2001 Inventory # 001568 W2-2 Purpose Demonstrate the application of friction in a contact analysis Goal Include friction in a contact analysis and compare the response to the solution involving frictionless surfaces Model Description 2D hyperelastic planer seal 1/2 symmetry Seal compression simulation Elastic Coulomb friction 2.Friction Planar Seal (part 2) 1/2 symmetry 0.85 inches applied displacement coefficient of friction = 0.2

3. Workshop Supplement October 15, 2001 Inventory # 001568 W2-3 2.Friction …Planar Seal (part 2) STEPS TO FOLLOW: 1.Start an ANSYS Interactive session in the working directory specified by the instructor using “seal2” as the jobname 2.Resume the SEAL (part 2) database –Utility Menu > File > Resume from Select “seal.db2” [OK] –OR enter the following command: RESUME, seal, db2 NOTE: The seal.db2 database contains the completed geometry, boundary condition, and loading definitions for this finite element model.

4. Workshop Supplement October 15, 2001 Inventory # 001568 W2-4 2.Friction …Planar Seal (part 2) 3.Enter the coefficient of friction material property –Main Menu > Preprocessor > Material Props > Material Models… Double-click Material Model 2 Double-click Friction Coefficient Enter 0.2 for MU [OK] (exit material menu) –OR enter the following commands: /PREP7 MP, MU, 2, 0.2 4.List the elastic constants for review –Utility Menu > List > Properties > All Materials, All Temps … –OR enter the following command: MPLIST, ALL

5. Workshop Supplement October 15, 2001 Inventory # 001568 W2-5 2.Friction …Planar Seal (part 2) 5.Apply 0.85 inches displacement in the -Y direction (vertical) –Utility Menu > Plot > Elements –Main Menu > Solution > Apply > Displacement > On Nodes Select node number 259 [OK] UY Displacement value = -0.85 [OK] –OR enter the following commands: /SOLUTION D, 259, UY, -0.85 Pick node number 259

6. Workshop Supplement October 15, 2001 Inventory # 001568 W2-6 2.Friction …Planar Seal (part 2) 6.Specify “Basic” solution control options –Main Menu > Solution > Sol’n Control Select tab: “Basic” Analysis Options = Large Displacement Static Time at end of loadstep = 0.85 Number of substeps = 25 Max no. of substeps = 200 Min no. of substeps = 10 All solution items Write every substep [OK] –OR enter the following commands: NLGEOM, ON TIME, 0.85 NSUBST, 25, 200, 10 OUTRES, ALL, ALL

7. Workshop Supplement October 15, 2001 Inventory # 001568 W2-7 2.Friction …Planar Seal (part 2) 7.Monitor the Y direction reaction force –Main Menu > Solution > Unabridged Menu > Nonlinear > Monitor Select node number 259 [OK] Variable 3 FY [OK] –OR enter the following command: MONITOR, 3, 259, FY 8.Solve the contact analysis –Main Menu > Solution > Current LS [OK] –OR enter the following command: SOLVE Pick node number 259 Note: This is similar to the response in the previous workshop. Hit OK to allow ANSYS to proceed and bisect.

8. Workshop Supplement October 15, 2001 Inventory # 001568 W2-8 2.Friction …Planar Seal (part 2) 9.Read the results for the last substep –Main Menu > General Postproc > Last Set –OR enter the following commands: /POST1 SET, LAST 10.Plot the deformed shape –Utility Menu > Plot > Results > Deformed Shape Def shape only [OK] –OR enter the following command: PLDISP

9. Workshop Supplement October 15, 2001 Inventory # 001568 W2-9 2.Friction …Planar Seal (part 2) 11.Define the reaction force variable –Utility Menu > Plot > Elements –Main Menu > TimeHist Postpro > Define Variables [Add] Reaction forces [OK] Pick node number 259 [OK] User-specified label = FORCE FY [OK] [Close] –OR enter the following commands: /POST26 RFORCE, 2, 259, F, Y, FORCE Pick node number 259

10. Workshop Supplement October 15, 2001 Inventory # 001568 W2-10 2.Friction …Planar Seal (part 2) 12.Graph the load vs. deflection curve –Main Menu > TimeHist Postpro > Graph Variables 1st variable to graph = 2 [OK] –OR enter the following command: PLVAR, 2 For EXTRA CREDIT, try modifying the graph settings to improve the quality of the graph.

11. Workshop Supplement October 15, 2001 Inventory # 001568 W2-11 2.Friction …Planar Seal (part 2) 13.Review the contents of the monitor file (seal2.mntr) NOTE: Including friction increased the total force needed to compress the seal about 10% from 7.9289 to 8.7057. (see workshop #1) NOTE: Including friction increased the total number of equilibrium iterations about 60% from 71 to 99. (see workshop #1)