Car Crash simulation

Objective

To perform an explicit dynamic analysis of car body having frontal crash test. Simulate the analysis for different cases by assigning different thickness to car body and determine the total deformation and equivalent stress in the model.

Case Setup

1. Material :

Structural Steel is applied to the Barrier, while Stainless Steel NL is assigned to car body.

Stainless Steel NL

2. Meshing:

Mesh element size is controlled by using face sizing by providing a sphere of influence at certain regions. Triangular mesh elements is assigned to car body & tetragonal elements are assigned to barrier.

3. Physical constraints or Boundary Conditions:

• Car Body is fixed at its position by providing fixed support boundary condition.
• A displacement boundary condition is provided to barrier along Z-axis. 750 mm displacement in 0.001 sec.
• Simulation is allowed to run for the time interval of 0.001 second.
• Energy error is set to 10.
• Parametric analysis is done for three different values of car body sheet thickness ( 5mm, 7.5mm, 10mm)

Fig. Fixed Support

Fig. Displacement Boundary Condition

Results

Case 1. For 5mm thick car body sheet

Total Deformation

Equivalent Stress

Case 2. For 7.5mm thick car body sheet

Total Deformation

Equivalent Stress

Case 3. For 10mm thick car body sheet

Total Deformation

Equivalent Stress

                                                                    Fig. Table of Design Point 

Result Summary

It is very clear from the results analysis that as we increase the thickness size of car body sheet, lesser deformation take place & more resistive stress is produced. This is in accordance with theoretical concepts that with increase in thickness, more & more material is added to resistive the deformation hence stress will increase & deformation will decrease.

 In first case, when thickness is 5 mm then total deformation is about 1616 mm. And when we increase the thickness to 7.5 mm deformation reduces to 1555 mm & for 10mm deformation further reduces to 1439 mm. While analyzing the stress results, in first case it is about 3941 MPa, then increases to 4428 MPa & for 10mm it increases to about 4507 MPa.  

Animation