Week 10 Bullet penetrating a Bucket Challenge

OBJECTIVE:Perform a Explicit dynamics analysis of a bullet penetrating into a bucket in ANSYS Workbench.

1. The bullet is assigned a material of tantalum with a rigid stiffness.
2. The bucket is assigned with three different material non linear materials

TASK

For this challenge, i would simulate a bullet penetrating into a bucket. I would need to use 3 different non linear materials for the bucket and analyse their behaviour for the same velocity of bullet. Attach an animation to show the behaviour in the three cases.

CONNECTIONS

• No contacts are defined in explicit analysis.
• We just assign frictionless contact to all bodies in Body Interactions.

MATERIAL

ALuminium Non-Linear Material

Stainless Steel Non-Linear Material

Magnesium Non-Linear Material

MESHING

• An edge sizing of 6mm is specified in the workpiece

ANALYSIS SETTING

1. End time : 0.01s
2. Maximum number of cycles :100000000
3. Energy error limit : 5

BOUNDARY CONDITIONS

• A velocity is assigned to the bullet (13900mm/s)
• A bottom surface of Bucket is fixed

OUTPUT REQUEST

ALuminium Non-Linear Material

1. Total Deformation (1390mm )

1. Equivalent Stress (1642.70 Mpa)

OUTPUT REQUEST

Stainless Steel Non-Linear Material

1. Total Deformation (1483.7mm )

1. Equivalent Stress (7330.60 Mpa)

Magnesium Non-Linear Material

1. Total Deformation (1390mm )

1. Equivalent Stress (3030.50 Mpa)

DISCUSSION

MATERIAL	DEFORMATION(mm)	STRESS (Mpa)	DENSITY (Kg/mm3)	YOUNGS MODULUS (MPA)
STAINLESS STEEL	1484	7330.60	7.75 e-06	193,000
MAGNESIUM	1390	3030.50	1.8 e-06	45,000
ALUMINIUM	1390	1642.70	2.27 e-06	71,000

The penetration of the bullet into the bucket purely depends on the density and young modulus of the material being used.

It is known that young modulus of a material is directly proportional to the hardness of that material. Therefore the higher the modulus, the harder the material which results in greater resistance to deformation. In this case more stress is needed to penetrate the material.

Stainless steel which has the highest density and modulus developed the highest stresses due to penetration resistant properties of the material.

CONCLUSION

This task was simulated succesfully and the effect of bullet striking a bucket was analysed and deduced.