bullet penetrating a bucket
Objective: Using three different non linear material for the bucket, we will have to simulate a bullet penetrating into bucket and analyse their behaviour.
Import the geometry into the explicit dynamics system and open in space claim to ensure that the geometry is allright. Materials selected for this simulations are copper alloy NL, magnesium alloy NL and stainless steel NL.
In the mechanical model cell, the stiffness behaviour of the bullet is set to rigid and the bucket set to flexible.
The material properties are shown below.
Material properties of copper alloy NL
Material properties of Magnesium alloy NL
Material properties of Stainless steel NL
Material properties of Tantalum
Contact : all the default contact were deleted.
Meshing: Using the edge filter the two outer edge of the bucket was selected and meshed using a element size of 5mm
Edge sizing
Analysis settings: end time for this simulations was set up for 0.01 sec with maximum energy error of 6. Rest of the setting was kept same.
Initial conditions: an Initial velocity of -139000mm/sec was given to bullet in the x component.
Boundary conditions : the lower face of the bucket was fixed using a fixed support and imposed velocity of -139000mm/sec was given to bullet in the x component.
Results:
Deformations:
- Copper alloy NL
- Magnesium alloy NL
- Stainless steel NL
Stress:
- Copper alloy NL
- Magnesium alloy
- Stainless steel
Comparison:
Avg stress vs time
Deformations vs time
Conclusion:
Young modulus (MPa)
Stainless steel NL 193000
Copper alloy NL 110000
Magnesium alloy NL 45000
From the stress vs time graph we can see that the stress in stainless steel is little higher compared to rest because the young mod of stainless steel is higher than other two. Higher young modulus means high stiffness and therefore more resistance will be offered by the materials giving rise to stress.
From the deformations vs time graph, we can see that deformations doesn\'t seem to change much in all the three cases.
also i noticed a point, total elapsed simulation time taken for these three cases was highest in case of stainless steel NL and lowest for magnesium alloy NL