Week - 4 - Crash Box Simulation
Crash Box Simulation
AIM:
In this assignment, the student needs to simulate a crash test for a crash box for which mesh is given. A crash box is a highly energy absorbing structure that crashes on application of loads and reduces impact on other components nearby. A full-fledges crashbox is a highly sophisticated design but in this case we will go with a rectuangular channel which can thought of as the most simple crashbox.
Here are the different assumptions and information required:
- The crashbox should crash into a rigidwall created using *RIGIDWALL_ keyword. Check the manual to understand and create a rigidwall.
- Material for the crashbox is steel. The simulation needs to be started using elastic material to verify its correctness and later a nonlinear material card data will be provided. Thickness of the crashbox is 1.2mm.
- Initial velocity for the crashbox should be around 50 kmph
- The units system to be used is gm-mm-ms
- The simulation should satisfy either of the two situations - (1) It crashes on the rigidwall and rebounces completely or (2) it buckles and folds in the axial direction so as to come in self-contact.
- Once the simulation is completed and results as asked for below is collected, run another simulation by increasing the thickness of the crashbox from 1.2 to 1.5mm.
PROCESS:
- Download the file and open in LS-dyna
- Rename the part name
- Assigne the section as 'shell'
- We go with given dimensions as in the question ( gm-mm-ms )
- Planer Rigidwall is made and is move the tail to -20mm apart from shell
- Apply the elastic material in MAT
- Provide velocity and keep it in given unit
- Create cs for SLEOUT
- Give the required outputs in DATABASE
- Go for LS-RUN.
Animation of the final simulation
- Cross-sectional force generated in the middle of the crashbox (along its length)
- Acceleration plot of a node in the middle of the crashbox (along its length)
- Maximum directional stress and strain along the length of the crashbox (X strain, Y strain etc)
Plot of all energies (total, internal, kinetic, hourglass, sliding)
For thickness 1.5mm
- Animation of the final simulation
- Cross-sectional force generated in the middle of the crashbox (along its length)
- Acceleration plot of a node in the middle of the crashbox (along its length)
- Maximum directional stress and strain along the length of the crashbox (X strain, Y strain etc)
- Plot of all energies (total, internal, kinetic, hourglass, sliding)
