Simulating a Deep Drawing Process Workshop 2

Workshop Supplement March 15, 2001 Inventory # WS2-2 Utility Menu > File > Read input from …> deep.inp > OK Exercise: Simulating a Deep Drawing Process Step 1. Read in the input file “deep.inp” The input file deep.inp creates a finite element model for the simulation of a deep drawing process. The model consists of a blank (metal sheet) that is deformed into the desired shape by the action of a rigid punch pressing it into a die. A blankholder limits the amount of wrinkling in the blank as it is pushed down into the rigid die by the punch, which travels at a prescribed velocity. All components are defined using shell elements. For the blank, five integration points are used through the thickness. Quarter symmetry is employed. After the input file deep.inp is read in, the explicit material properties, loading conditions, and contact conditions are defined and the problem is solved.

Workshop Supplement March 15, 2001 Inventory # WS2-3

Workshop Supplement March 15, 2001 Inventory # WS2-4 Step 2. Define the material model for the blank (MAT 1) –Preprocessor: Material Props > Define MAT Model … > Add …> Plasticity > Bilinear Kinematic > OK

Workshop Supplement March 15, 2001 Inventory # WS2-5 Enter the nonlinear material properties for the blank (MAT 1) as shown below: Then pick OK

Workshop Supplement March 15, 2001 Inventory # WS2-6 Preprocessor: Material Props > Define MAT Model … > Add … > Other > Rigid > OK Step 3. Define the material models for the punch (MAT 2), the blankholder (MAT3), and the die (MAT4). A rigid material condition will be specified for all three, but the applied constraints will be different.

Workshop Supplement March 15, 2001 Inventory # WS2-7 Enter the same density, elastic modulus, and Poisson’s ratio for the rigid punch, blankholder, and die. Note, however, that the constraints are different. Punch (MAT 2) Blankholder (MAT 3) Die (MAT 4) The die (above) is completely fixed. Both the punch and the blankholder are free to translate in the Z direction, but are fixed in all rotations. … CLOSE

Workshop Supplement March 15, 2001 Inventory # WS2-8 Utility Menu > Parameters > Array Parameters > Define/Edit … > Add … Dimension VTIME to be 11x1x1 > OK Step 4. Specify the punch velocity by defining two arrays, VTIME and VLOAD. First define the array VTIME to contain the times at which the punch velocity is specified.

Workshop Supplement March 15, 2001 Inventory # WS2-9. Use the downward arrow button to access the 11th value, then select: File > Apply/Quit Select the array VTIME and pick “Edit …” to fill in the time values shown below:

Workshop Supplement March 15, 2001 Inventory # WS2-10. Likewise, define and fill the array VLOAD for the corresponding punch velocities: Close window when done...

Workshop Supplement March 15, 2001 Inventory # WS2-11 Then review the list... And choose File->Close... Step 5. Create the PART list which will be used in specifying some of the loads Preprocessor: LS-DYNA Options > Parts Options > Create Part > OK

Workshop Supplement March 15, 2001 Inventory # WS2-12 … OK Step 6. Enter Solution Apply the velocity load (RBVZ) to the rigid punch (PART 2) Solution: Loading Options > Specify Loads

Workshop Supplement March 15, 2001 Inventory # WS2-13 FTIME = ( 0, 200 ) FLOAD = ( -10, -10 ) Step 7. Specify the blankholder force by defining two arrays, FTIME and FLOAD. –Utility Menu > Parameters > Array Parameters > Define/Edit … > Add … –Dimension both FTIME and FLOAD to be 2x1x1 > OK –Utility Menu > Parameters > Array Parameters > Define/Edit … > Edit … –File > Apply/Quit when done...

Workshop Supplement March 15, 2001 Inventory # WS2-14 … OK Step 8. Apply the force load (RBFZ) to the rigid blankholder (PART 3) Solution: Loading Options > Specify Loads

Workshop Supplement March 15, 2001 Inventory # WS2-15 … Apply Step 9. Return to the Preprocessor to Define Surface-to-Surface contact between the blank (PART 1) and the punch (PART 2). Specify the static friction coefficient to be 0.1 and the viscous damping coefficient to be 10. Preprocessor: LS-DYNA Options > Contact > Define Contact …

Workshop Supplement March 15, 2001 Inventory # WS2-16 … OK … Apply Step 10. Likewise, define Surface-to-Surface contact between the blank (PART 1) and the blankholder (PART 3) and between the blank and the die (PART 4). Use the same coefficients as in the previous contact definition. Preprocessor: LS-DYNA Options > Contact Optns > Contact Param …

Workshop Supplement March 15, 2001 Inventory # WS2-17 … OK Step 11. Specify the multi-surface shell thickness option to use the shell mid-plane as the contact surface for the rigid tooling. The actual shell thickness of the blank will still be used with this selection. Preprocessor : LS-DYNA Options > Contact > Advanced Control...

Workshop Supplement March 15, 2001 Inventory # WS2-18 … OK Step 12. Specify the shell thickness change option. Preprocessor : Shell Element Ctrls...

Workshop Supplement March 15, 2001 Inventory # WS2-19 … OK Solution: Output Controls > File Output Freq->Number of Steps... … OK Step 13. Return to Solution to define the solution controls. Solution: Time Controls > Solution Time...100

Workshop Supplement March 15, 2001 Inventory # WS2-20 The SOLVE command automatically creates the LS-DYNA keyword input file “Jobname.k” and the headers to the.RST and.HIS files. Step 14. Select everything, SAVE the model, and SOLVE the simulation. –Utility Menu > Select > Everything –ANSYS Toolbar > SAVE_DB –Solution: Solve > OK

Workshop Supplement March 15, 2001 Inventory # WS2-21 Step 15. Enter the General Postprocessor and examine the final deformed shape for the last set of results. –General Postprocessor: -Read Results- Last Set –Utility Menu > Plot Ctrls > Style > Displacement Scaling > DMULT = 1.0 (true scale) –General Postprocessor: Plot Results > Deformed Shape > OK