Week 10 Bullet penetrating a Bucket Challenge

OBJECTIVE:

• The main objective of this challenge is to perform explicit dynamic analysis of a Bullet penetrating a Bucket and to simulate a bullet penetrating into a bucket by using 3 different non linear materials for the bucket and to analyse their behaviour for the same velocity of bullet. We have to apply the conditions for bullet as mentioned in the video and to analyse the total deformation and Equivalent stresses acting on the model.

INTRODUCTION:

• The CAD Model of Bullet penetrating a Bucket is shown in below figure. The model consists of a bullet and a bucket. The behaviour of three different material is analysed by using same velocity for all materials and the material is analysed by striking of bullet into the bucket. The bucket is divided into two parts where the bullet strikes the bucket.

PROCEDURE:

CASE-1 ALUMINUM ALLOY NL

• Open the ANSYS Workbench software. Under the Analysis system select the Explicit Dynamics and wait for few seconds to pop up the window, which contains Engineering data, Geometry, Model, setup, Solution and Results.

• Under geometry import the Bullet penetrating a Bucket model.

• Update the model by right click and edit the Model for Preprocessing.

• Wait for few seconds and ANSYS Mechanical will open as shown below. Rename the model as Bullet and Bucket. Make the behaviour of the bullet as Rigid.

• Assign the material to the model. Right click on engineering data and under engineering data sources select explicit materials and assign tantalum to the bullet and under nonlinear material assign aluminum NL to the bucket.

• Connections: Delete the default contact and under body interactions make sure that the type as frictionless.

• In ANSYS automatic mesh will be performed with Default mesh size, so select the sizing option, select the edge option and select the edges as shown and assign a element size of 6mm.

Mesh

Analysis settings:

• Fixed support: Insert a fixed support to the bucket body and select the face as shown below.

• Velocity: Insert a velocity to the bullet body and select the body as shown below. Change define by components and select the X-direction and assign a value of -139000mm/s.

• Now request for the outputs such as equivalent stress, equivalent elastic strain and Total deformation.

CASE-2 COPPER ALLOY NL

1. Assign the material to the model. Right click on engineering data and under engineering data sources select explicit materials and assign tantalum to the bullet and under nonlinear material assign Copper NL to the bucket.
2. For remaining steps follow the same procedure as mentioned in Case-1 Aluminum alloy NL Material.

CASE-3 MAGNESIUM ALLOY NL

1. Assign the material to the model. Right click on engineering data and under engineering data sources select explicit materials and assign tantalum to the bullet and under nonlinear material assign Magnesium NL to the bucket.
2. For remaining steps follow the same procedure as mentioned in Case-1 Aluminum alloy NL Material.

SIMULATION RESULT:

CASE-1 ALUMINUM ALLOY NL

• Total Deformation:

Equivalent Stress:

• Equivalent Strain:

Tabular results: Using Parametric study For other two cases

CONCLUSION:

• From the above results we can conclude that the Highest equivalent stress of 334.48 MPa is experienced, in Magnesium alloy NL and Lowest equivalent stress of 146.03 MPa is experienced in aluminum alloy NL, and a moderate equivalent stress of 275.49 MPa is experienced in Copper alloy.

• Max Equivalent Elastic Strain of 0.72695 is experienced in Magnesium alloy NL, Max Equivalent Elastic Strain of 0.0030566 is experienced, in copper alloy NL and Max Equivalent Elastic Strain of 0.0027468 is experienced in Aluminium alloy.

• The Max Total deformation of 1739.9 mm in Magnesium alloy NL Material and other cases having 1390mm same deformation

Animations:

• Total Deformation: