Week 10 Bullet penetrating a Bucket Challenge

Structural Analysis of a bullet Penetrating into a Bucket in ANSYS Workbench

Aim: To Perform explicit dynamics structural analysis of a bullet penetrating into a bucket by selecting three different nonlinear materials for the bucket and find out the equivalent stress and total deformation in each case.

Model:

Materials:

1. Thallium
2. Aluminum Alloy NL
3. Copper Alloy NL

Procedure:

First, I can drop explicit dynamics into the project schematic and add the above materials.

Then, I opened the Spaceclaim and import geometry. Once the geometry is loaded the I can check the model and find any abnormalities and close the SpaceClaim.

In ANSYS Mechanical, I set Material for the bucket is Thallium. ANSYS is predefining contact. In this case the contact is defined by bonded, but this is not needed. So I can delete this and go to the next step.

Mesh Generation:

In Geometry, the bullet is set into rigid, because we only check the bucket stress and bullet does not deformable. I set mesh size is 10mm and generate mesh as per default meshing.

Analysis Setting:

In explicit dynamics simulation, the time step required is very well, so I set the end 1.e-002 and maximum energy is 5.

Fixed Support:

In this case, The bullet is movable and the bucket is stationary. So I can fix the bucket using the face selection tool.

Velocity:

Now, here the bullet velocity is so high, so I can set into -1.39+005 mm/s into -x-direction.

Post-Processing:

Case_1:

Material: AL 1100- O

Total Deformation:

Equivalent Stress:

Aluminium Alloy NL

Total Deformation:

Equivalent Stress:

Copper Alloy NL

Total Deformation:

Equivalent Stress:

Results:

Comparison Three Cases

	AL -1100 - O	Aluminium Alloy NL	Coppe Alloy NL
Total Deformation	1390 mm	1390 mm	1390 mm
Equivalent Stress	235.49 Mpa	3020 Mpa	2340.7 Mpa

Conclusion :

When a bullet tries to penetrate to any object, then how bullets can penetrate is totally depends on the bullet material & Velocity and Bucket Density & Hardness.

Hardness and density will resist to penetration. Density is mass per unit volume. The higher density of material means higher mass per unit volume which tries to block the penetration.

Here, The density is shown in the material property and it is different in all cases lowest density is Al-1100-O which is 2707 kg/m^3. So, Penetration will be higher on that material.

In the case of a bucket of copper alloy NL, the density is higher so it will block the penetration means less deformation which is satisfying results.

Equivalent stress is different in all three cases and the maximum in Copper alloy NL