Bullet penetrating a Bucket Challenge

AIM:

To simulate a bullet penetrating into a bucket using 3 different non linear materials for the bucket and analyse their behaviour for the same velocity of bullet

INTRODUCTION:

Terminal ballistics (also known as wound ballistics), a sub-field of ballistics, is the study of the behavior and effects of a projectile when it hits and transfers its energy to a target. Bullet design and the velocity of impact largely determine the effectiveness of its impact.While the concepts of terminal ballistics can be applied to any projectile striking any target, much of the topic concerns the effects of small arms fire striking live targets and their ability to either incapacitate or kill them. Common factors include bullet weight, composition, velocity, and shape.

Most penetration analysis and armor design in the past have dealt with cartridges that have military-style steel jacketed and armor-piercing bullets. Body armor studies have typically focused on handgun ammunition. These types of analyses are usually carried to develop the material which can resist the bullet up to some extent. So, the material can be used as bullet-proof. Thus by comparing the behavior of different materials on the penetration of the bullet, we can find or develop a bullet-proof material.

GEOMETRY:

MATERIALS USED:

BUCKET

BULLET

PROCEDURE:

• Import model in Explicit Dynamics in Geometry section.
• Now we import the geometry and open it in spacecalim and check for any abnormalities
• Then go to the ANSYS Mechanical model section.
• Check or Rename the Part of the setup as “Bucket” & “Bullet” as shown in above geometry image.
• Now we have to mesh the component. We apply an edge sizing for a finer mesh in the deformation area
• Edge Sizing: 2 Edges ,Element Size: 6 mm
• 
• After the meshing procedure is carried out now we have to apply the boundary conditions

Analysis Settings:

• No.of Steps: 1
• End Time: 0.01 s
• Maximum Number of Cycles:1e+07
• Maximum Energy Error: 5
• Initial Time Step: Program Controlled
• Minimum Time Step: Program Controlled
• Maximum Time Step: Program Controlled

Fix Support (For CASE_1, 2,& 3):

• Keep bottom face of the Bucket as a fixed to hold it while the bullet is penetrating.

Velocity (For CASE_1, 2,& 3):

• Apply velocity to Bullet in the negative X-Direction as given below:

• Here the velocity of the Bullet is 1390000 mm/s.

Solution:

• After giving proper boundary conditions, create desired solutions for output results.
• Create Solutions for :
  • Total Deformation
  • Equivalent Stress

RESULTS:

CASE I: COPPER ALLOY

EQUIVALENT ELASTIC STRAIN

TOTAL DEFORMATION

EQUIVALENT STRESS

CASE II: MAGNESIUM ALLOY

TOTAL DEFORMATION

EQUIVALENT STRESS

EQUIVALENT ELASTIC STRAIN

CASE III: TITANIUM ALLOY

TOTAL DEFORMATION

EQUIVALENT STRESS

EQUIVALENT ELASTIC STRAIN

CONCLUSION:

• From the results, we can conclude that Titanium Alloy has the highest strength and higher young’s modulus, so the stress is also getting higher. So it is capable to resist penetration.
• Generally the materials like Kevlar are use as bulletproofing, which resists the bullet easily and also light in weight.
• Main objective of these type of analyses is to find the material for damage reduction and deviation.
• Damage reduction reduces the damage a bullet does per inch of the material it passes through.
• Effect of penetration depends on the thickness and the density of the material.
• In our case, for Titanium Alloy, we can observe the stretching of the material on penetration due to its flexibility.
• So, high strength and density also decrease the penetration with an increase in stress.
• In the Titanium Alloy NL case, stress is higher, which means the plastic deformation of the material is large. So the resistance to the penetration will also be higher.
• So, due to high strength and high density, it gives less penetration gives less damage.