workshop 9 taylor impact test – “what if” study

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February 27, 2009Inventory #002665

Workshop 9

Taylor Impact Test – “What if” Study

ANSYS Explicit Dynamics

Workshop 9. Taylor Impact Test – “What if” Study



Training ManualWorkshop Goal and Procedure

Goal: Conduct “what if” study on previous Taylor impact test model by tracking

maximum equivalent plastic strain as a function of initial rod velocity.

Procedure:Duplicate the existing Explicit Dynamics (ANSYS) Analysis System ProjectAssign a parameter to the initial velocity condition of the rodAssign a parameter to the maximum equivalent plastic strain Run the parameterized system from the Project SchematicReview the results – Equivalent plastic strain plots are shown below

corresponding to the initial velocities indicated above each image:

Vz = -100 m/sec Vz = -300 m/sec Vz = -500 m/sec




Training ManualAbbreviations used in Procedural Steps

As in the preceding workshops, the following abbreviations are used:– DC = Double Click with Left Mouse Button– SC = Single Click with Left Mouse Button– RMB = Right Mouse Button Selection– D&D = Drag and Drop = Hold Left Mouse Button down on item while

dragging it to new location and then release it (i.e., Copy or Move)

Note: Throughout these Workshops, the procedures shown are not always the only way to accomplish the desired tasks, so feel free to investigate the other methods outside of this course. Consult the documentation for additional details.




Training ManualStep 1 – Duplicate the Existing Project System

1.a Start ANSYS Workbench and open the Project taylor_basic.wbpj

1.b Copy the Project to taylor_what_if.wbpj via the Save As icon.




Training ManualStep 1 – Duplicate the Existing Project System ...

1.c Edit the Setup cell in the new Project System.

RMB SC

1.d Verify that the MKS unit system is still active.




Training ManualStep 2 – Parameterize the Initial Velocity

2.a Select the Velocity branch under the Initial Conditions branch in the tree.

2.b Click on the empty box to the left of the Z Component. A blue “P” will appear in the box indicating that the value is now a parameter.

This input parameter will be controlled from the Project Schematic. Initial velocities of 100 m/sec and 500 m/sec will also be studied.

SC

SC




Training ManualStep 3 – Parameterize the Max Eqv Plastic Strain

3.a Select the Equivalent Plastic Strain branch under the Solution branch in the tree.

3.b Click on the empty box to the left of the Maximum Result. A blue “P” will appear in the box indicating that the value is now a parameter.

This output parameter will be a function of the initial rod velocity, which will be controlled from the Project Schematic. Since it is plastic strain, the final result is sufficient, as the maximum plastic strain that occurs over time will still exist at the end of the run, assuming no erosion occurs.

SC

SC




Training ManualStep 4 – Modify the Input Parameter

4.a Return to the Project Schematic and access the Parameter Set.

DC

Input parameter P1 currently has a single design point defined (VZ = -300 m/sec)

Parameter Outline appears at top left of Project Schematic




Training ManualStep 4 – Modify the Input Parameter ...

Design Point Table appears at top right of Project Schematic

4.b Define two new initial velocity conditions (-100 and -500 m/sec) by typing them in underneath the current -300 m/sec condition. Design Points DP 1 and DP 2 will be created.

4.c Export the results to retain them.




Training ManualStep 5 – Solve the Design Points

5.a Run the new model configurations via Update All Design Points

5.b Acknowledge the condition of closing some of the editors while the design points are being updated.




Training ManualStep 5 – Solve the Design Points ...

5.c After each solution is completed, the output parameter is recorded.

Wait until all of the solutions have finished before proceeding. The maximum equivalent plastic strains are now shown for the three input conditions.

5.d Save the Project before continuing on.




Training ManualStep 6 – Review the Directory Tree

6.a Review the directory tree to verify that each design point was saved via the Export option in Step 4.c.

6.b The directory tree is very complex; always use the Archive feature to pack files for distribution to other ANSYS users.

Folder contains:

Mechanical database

DM geometry database

ANSYS AUTODYN files

(Vz = -100 m/sec)

(Vz = -300 m/sec)

(Vz = -500 m/sec)




Training ManualStep 7 – Load the Different Design Points

Since each new design point is saved as a separate project (i.e., taylor_what_if_dp1.wbpj and taylor_what_if_dp2.wbpj), there is no way to view them all in the same project. A given design point can be copied to the current project, but only the input is copied and not the output - even if the results were saved via the Export option. Updating the current design point initiates a new solution with the newly defined “current” parameter set. However, subsequent versions of ANSYS Workbench will allow the Parameter Manager to create new systems in the same project, making it easier to track.

7.a Therefore, load each project in turn to view the results. Initially, view the results from the current project (taylor_what_if.wbpj) that is based on an initial projectile velocity of Vz = -300 m/sec.




Training ManualStep 7 – Load the Different Design Points ...

7.b Edit the Results Cell to see the current design point results. The Mechanical application will then open for the current project (taylor_what_if).

7.c To better view the plastic strain in the projectile, Hide the Plate Body.

7.d Next select Equivalent Plastic Strain

RMB

RMB





Note: The value reported earlier by the Parameter Manager for the initial velocity of Vz = -300 m/sec is shown as the maximum plastic strain obtained.

7.e Repeat this procedure (Steps 7.b through 7.d) to view the results for Design Point #1 after opening project taylor_what_if_dp1






7.f Repeat this procedure again to view the results for Design Point #2 after opening project taylor_what_if_dp2





Training ManualStep 8 – Additional Studies

8.a If time permits, investigate other parameter combinations. First save the original project as a new project called taylor_new.wbpj

8.b Check the filtering prefixes for the geometry parameters. The default prefix of DS limits only those parameters that begin with DS to be brought into Mechanical ...




Training ManualStep 8 – Additional Studies

8.c Edit the Geometry Cell to parameterize some of the dimensions.

RMBSC

8.d Select the Sketching tab and activate the sketch Sketch1 (assuming you used the default name).

8.e Enter the parameter name of DS_XYPlane.R1




Training ManualStep 8 – Additional Studies ...

8.f Edit the Engineering Data Cell to parameterize some of the material properties.

RMBSC

8.g Select the Engineering Data material library and highlight the Structural Steel NL material model.

This material is that used by the plate. A softer material will allow for more penetration by the projectile.

SC

SC





8.h Expand the Physical Properties Isotropic Elasticity and Bilinear Isotropic Hardening.

8.i Expose the parameters Young’s Modulus and Yield Strength.

8.j Return to the Project Schematic.

Note: Be especially careful in deciding values for these parameters, as the physics of the problem may change. Erosion controls may be necessary to prevent the time step from dropping to zero ...





8.k Return to the Project Schematic and access the Parameter Set.

RMB SC

Note:

Three new parameters have been added to the Input Parameter Set.





8.l Create a new design point (or multiple points) as the one shown below. Be sure to Export the results to save them to the disk.

8.m Update the new design point. Since the Project taylor_new.wbpj was copied from another project, all of the design points technically need to be updated. Therefore, just run the new design point by itself to save time.

RMB

SC





Note: The maximum equivalent plastic strain is now 75.503%.

8.n As before, save the current project and open taylor_new_dp3.wbpj that corresponds to the new design point to investigate the results.





8.o Edit the Results Cell

RMB SC8.p Review the plastic strain results.

8.q Finally, exit the project.

workshop 9 taylor impact test – “what if” study

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