Week 11 Car Crash simulation

AIM:

• To perform explicit dynamic car crash simulation and parametric study using 3 different values of thickness for the car body.

PROCEDURE:

• Open ansys workbench.
• Drop Explicit dynamic analysis system and rename it as car crash simulation.

• Import geometry by browsing to the file location.

• Add Stainless Steel NL from engineering data resources.

• Open geometry using Spaceclaim to check the abnormalities in the geometry and close Sapceclaim.

• Open Ansys mechanical to set up the simulation.
• Assign the thickness to the car body as 0.3mm.
• Assign Stainless Steel NL material to the car body.

• To perform the parametric study for different thickness values mark the check box in front of the thickness as below.

• Create the symmetric regions for both wall and car body as shown below.

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• For explicit dynamics, analysis contacts are not needed so delete the default contacts.
• Now under mesh insert method as triangles and insert face sizing of 400 mm element size.
• Insert tetrahedron mesh method for the wall.

• Change the smoothening to low and generate the mesh.

• The above graph represents mesh metrics which gives the element quality and type of elements used for the simulation.
• Apply fixed support to the car body using a face filter.

• Apply displacement of 500 mm to the wall along the z-direction.

• Under analysis, settings change the end time to 0.001.
• List the outputs required and turn on the parametric study option for the outputs to obtain results for different car body thicknesses.
• Now run the simulation to obtain results.
• Now close ansys mechanical and open parametric set and give different thickness values to the car body and click on update all design points to obtain the results.

RESULTS:(CAR BODY THICKNESS-0.3 mm):

TOTAL DEFROMATION:

DIRECTIONAL DEFORMATION:

EQUIVALENT STRESS:

RESULTS:(CAR BODY THICKNESS-0.5 mm):

TOTAL DEFORMATION:

DIRECTIONAL DEFORMATION:

EQUIVALENT STRESS:

RESULTS:(CAR BODY THICKNESS-0.7 mm):

TOTAL DEFORMATION:

DIRECTIONAL DEFORMATION:

EQUIVALENT STRESS:

SL.NO	THICKNESS	EQUIVALENT STRESS	DIRECTIONAL DEFORMATION	TOTAL DEFROMATION
1	0.3 mm	4089.3 MPa	53.261 mm	883.3 mm
2	0.5 mm	4089.4 MPa	52.108 mm	881.39 mm
3	0.7 mm	4095 MPa	51.535 mm	881.01 mm

CONCLUSIONS:

• Explicit dynamic analysis on the car front crash is performed successfully using ansys workbench and results are obtained for the three-car body thicknesses using parametric study.
• In case-3 as the thickness is 0.7mm the directional deformation and total deformation is less compared to the case-1 and case-2 but it is too small to consider for a design hence from the results obtained the 0.3 mm thickness car body design is safe for manufacturing. The results of the 0.7 mm thickness car body and 0.5 mm thickness car body are too close to the 0.3 mm thickness car body hence 0.3 mm thick car body is sufficient to withstand the applied load.