Week 10 Bullet penetrating a Bucket Challenge

OBJECTIVE

To simulate a bullet penetrating into bucket  using Explicit dynamics

Case 1  Stainless  Steel NL

Case 2 Alumimum Alloy NL

Case 3 Copper Alloy NL

PRODECURE

Create Explicit Dynamics in Ansys Workbench and in Engineering data select  the material Tantalum from explicit materials and Stainless Steel Nl , Aluminium Alloy NL and Copper Alloy NL according to the cases

Tantalum

Import the geometry and check in Spaceclaim for any irregularties

Then open Ansys mechanical and rename the components as bucket and bullet then assign the Tantalum material to the bullet and Stainless Steel NL , Aluminium Alloy NL and copper Alloy NL material according to the cases to the bucket and change the stiffness behaviour of the bullet to rigid

                                                          

Body Interaction - No contacts are defined .Instead a body interaction is introduced the parameters of which are set as shown below

   

Mesh  Edge Sizing  The bucket is meshed by elements size of 6mm along its edges

 

Mesh 

    

Analysis Settings   Set time as 1e-2 with maximum number of cycles as 1e+7 Maximum Error set to 5

Fixed Support  Bucket is fixed

                                                      

Velocity   Bullet provides the velocity of 139000mm/s in negative x direction

                                                     

Run the simulation and results obtained

Result  The analysis  runs successfully and results obtained

Case 1 Stainless Steel NL

Total Deformation  Max - 1390mm

                                                

                                               

Equivalent Stress Max - 1286.4 Mpa

                                                 

                                                 

Energy Conservation Plot

                                              

Equivalent Stress

                                                   

                                                   

Case 2 Aluminium Alloy NL

Total Deformation Max - 1390mm

                                                       

                                                       

Equivalent Stress Max - 1059.7 Mpa

                                                         

                                                         

Energy Conversion Plot

                                                        

Equivalent Stress

                                                        

                                                      

Case 3 Copper Alloy NL

Total Deformation Max - 1390mm

                                                

                                              

Equivalent Stress Max - 2046.1Mpa

                                             

                                              

Energy Conversion Plot

                                             

Equivalent Stress

                                          

                                          

CONCLUSION

• Total Deformation in case 1 and case 2 and case 3 is the same as the distance that is transversed by thye bullet in 0.01s
• The  highest stress is observed in case of copper alloy nl indicating that copper alloy , offered the maximum resistance to the incoming bullet than the other two materials