Car Crash simulation using Ansys
Objective - To perform a parametric analysis of a frontal car crash setup and determine the effect of varying the thickness of the model on Equivalent Stress and Total Deformation.
Case 1 - 0.3 mm.
Case 2 - 0.5 mm.
Case 3 - 1.0 mm.
Procedure -
Create Explicit Dynamics in Ansys workbench and in engineering data select Stainless Steel NL and Structural Steel.
Stainless Steel NL.
Structural Steel.
Import the geometry and check in SpaceClaim for any irregularities.
Then open Ansys mechanical and rename the component as CarBody and Wall then assign the Stainless Steel NL material to the CarBody and Structural Steel material to the cases to the Wall.
Symmetry Definition - The entire setup mentioned above represents just half the model. The analysis is carried out on a half model to reduce computation time. To get results for the full model, two symmetry regions are defined about which the results of the half model are duplicated.
Body Interactions - No contacts are defined. Instead a Body Interaction is introduced, the parameters of which are set as shown below.
Mesh - The wall is meshed using Tetrahedrons and by Patch Conforming Method and CarBody by using default mesh size.
Analysis Settings - Set end time as 1e-3, with maximum number of cycles as 1e+7, Maximum error set to 0.1.
Fixed Support - Rear surfaces of the CarBody are provided a fixed support.
Displacement - Wall is provided a displacement of 500mm in the Z-direction.
Parameter Definition - Instead of running separate simulations to get the results, a parametric option used.
The thickness of the Car Body is set as the input parameter.
For the output parameter, the Total Deformation and Equivalent Stress and Equivalent Stress on the Car Body are set as the output parameters.
Run the simulation and results obtained.
Result -
The project interface page appears as below, with a parameter set option. Double clicking that option opens up the results to the simulations.
The results page from the parameter set page appears as below
Case 1 - 0.3 mm.
Total Deformation Max - 1042 mm
Equivalent Stress Max - 10764 Mpa
Equivalent Stress Car Body Max - 3890.6 Mpa
Energy Conservation Plot
Animation - Total Deformation
Case 2 - 0.5 mm.
Total Deformation Max - 1037.9 mm
Equivalent Stress Max - 10721 Mpa
Equivalent Stress Car Body Max - 4494.6 Mpa
Energy Conservation Plot
Animation - Total Deformation
Case 3 - 1.0 mm.
Total Deformation Max - 1026.9 mm
Equivalent Stress Max - 10604 Mpa
Equivalent Stress Car Body Max - 3784.6 Mpa
Energy Conservation Plot
Animation - Total Deformation
Conclusion -
- Maximum deformation is developed for Case 1 - 0.3mm because of lowest stiffness or rigidity to resist deformation.
- Maximum Stress is developed for Case 1 - 0.3mm because it has minimum thickness so induces maximum stresses due to less resisting area. The model experiences the highest Von-Mises stress when the thickness of the shell is the least.
Google drive link - https://drive.google.com/file/d/1K2wiSc6dX7y92TpZWmq8Wy6EdhybOakn/view?usp=sharing