Week - 3 Drop test Challenge

Objective:

To create a basic simulation for drop test of a mobile on rigid plate

Procedure:

• Open LS prepost and import the keyword file. Go to keyword manager to create and manage different cards.
• Choose unit system and convert all the relevant properties in those units. Here we have used g-mm-s
• Create two material cards for mobile and base as shown in figure

• Create sections. 1 shell for top base plate, 1 solid for bottom base plate and 1 solid for mobile

• Assign shell id and material id to respective individual part ids to the section and material properties to the components.

• Now create contact -> automatic surface to surface. The contact is between the mobile and top plate

• Create control termination card to input the run time of simulation i.e. 0.1 s.

• To create output we need create a binary output file using d3plot keyword. Also to assess energies go to ASCII and select GLSTAT and MATSUM. Assign dt = 0.0005 in all three cards.

• Now we need to assign boundary conditions to the model
• For that go to create entity - > boundary -> spc -> select nodes on the edges of base plate. Restrict all DOFs to restrain the movement
• Also to give velocity of drop, go to input -> velocity -> selective mobile (using nodes or part) -> give velocity Vz = -10000 mm/s.

• Perform a model check using model check -> keyword check, to see if there are any errors or warning.
• Now go to title card and rename the keyword file as Drop_Test
• Now save the keyword file and run the simulation using solver.

Results:

• To check the results open LS prepost -> open binary plot -> d3plot.
• Check the animation for the impact.
• Plot Von misses stress, mean strain, Kinetic Energy at point impact. Other data can be extracted as per requirement which isn’t a necessity here

Conclusion:

This activity was a trial simulation for drop test. It helped us understand the key steps involved in building a simulation keyword file. It gets us familiar with the tool and different steps involved.