Assignment 7-Side Pole Crash Simulation Challenge

AIM:

To perform Side Crash simulation for the given BIW structure using Radioss and HyperCrash.

CAR MODEL:

               

               

PROCEDURE:

• Import the starter file into the Radioss profile.

• Check unit system in the BEGIN_CARD in the Solver tab. With reference to this unit system all input values are given throughout the procedure.

           

• Create Type7 interface along with recommended parameters (friction=0.2) and select the components in the model.

         

• Review and check the Interface contacts.

   

• Select penetration check option from the Tools menubar. 
• Ensure zero penetration error for the model.

         

• Select and open the Mass details option from Tools menubar.
• Check the mass, which is 165 kg and the COG which can be viewed by creating node at the given coordinates.

           

           

• The required value of total mass is supposed to be 700kg and the recommonded position of the COG is more towards the cross frame near to the driver seat.
• Create or add extra mass to nodes using ADMAS card. The mass addition is to be adjusted more towards the middle frame (right side) region to obtain proper COG.

         

• Check the total mass and COG.

         

       

• Create a Rigid wall (cylinder) with friction=0.1, radius=254 and define XM,YM,ZM (wall plane coordinate) and  Normal direction.
• Set a secondary search distance of 1000 that highlights the nodes(yellow) 

             

• Create and apply an Initial velocity of 20mph(8.94mm/ms) for all nodes.

                  

• Check and set the runtime to 80ms and time step to 0.5ms

                   

• Export the model as rad file from Hypermesh. 
• Open new HyperCrash window (kN mm ms kg) and import the rad file.
• Run the Model checker available in the Quality menubar and check for errors.
• Warnings are reviewed for any critical effects and ignored if posssible. 

         

• Export the model rad file from HyperCrash and import and open the model into Radioss profile.
• Create Moving frames for the Cross-sections where the force variation has to be obtained.

         

• Create the section(plane) w.r.t Moving frames and select the elements.

         

• Create TH card and assign the cross-sections for plotting the section output.

         

• Create TH card and assign the node(inner door) for plotting the velocity output.

           

• Create spring elements connecting nodes from one side to opposite side nodes near Hinge pillar, B-pillar and Fuel tank.    

         

• Assign spring property card for the above elements with lower stiffness value.

         

• Low stiffness springs can be used to determine the intrusions during the crash.
• Create TH card for spring to obtain enlongation output.

         

 RESULT:

             

       

       

       

       

• A significant velocity drop is observed in the inner door node, reduces the impact on the driver side.
• Fuel tank region undergoes a displacement upto 250mm which is not ideal. Reinforcing the region to avoid punturing is necessary.
• Each frame carries an impact force close to 2.5kN during the crash.