Week - 4 - Crash Box Simulation

Aim: To perform a crash test of a crash box using Ls-Dyna.

Objective:

• To create a rigid wall in LS-Dyna
• Apply initial velocity of 50 kmph to the crash box.
• Run the simulation and compare results of crash box having thickness 1.2 mm and 1.5 mm respectively.
• The unit system followed is gm-mm-ms
• Plot the cross-sectional force generated in the middle of the crash box.

Procedure:

1.1)First we open the .K file in LS-PrePost

• 

1.2) Creating material:

• To create a material card, open keyword manager >> material >> Mat 024. Enter the values as shown below and change the title to crash_box.
• 

1.3) Creating sections:

• Shell section card is created and assigned to the Crash box.
• 

1.4) Defining part:

• Shell id and Material id are assigned by creating a part.
• 

1.5) Defining a contact:

• A contact - Automatic single surface contact is defined between the crash box and rigid wall.
• 

1.6) Defining velocity:

• Velocity of 13.9 mm/ms in x direction is assigned to the crash box.
• 

1.7) Defining Runtime:

• Control termination card is created to define the end time of the simulation.
• 

1.8) Output requests:

• To request output, Binary 3Dplot and ASCII card are created.
• 
• 

1.9) After assigining all keywords , we run the .k file in LS-Run.

• 
• After the message Normal termination is shown, our plot is completed.

Results:

• To check the simulation results, open Ls- Prepost >> binary plot >> d3plot.
• To check the von mises stress, go to post >> fringe component >> select the respective component.
• 

Conclusion : Simulation is carried on crash box with thickness 1.2mm and 1.5mm and requested outputs are obtained.