Assignment 6-Frontal Crash Simulation Challenge

Aim :-

Perform frontal crash simulation of the given vehicle front body using Hypermesh Radioss solver.

Procedure :-

1. Import the 0000.rad filke into the hypermesh with Radioss profile.

                                                     Fig 1 :- Model Imported

2. Check for unit system by Model browser->cards->Begin Card.

                   Fig 2 :- Unit Check

3. Type7 contact is created with recommended properties and friction = 0.2, Include all 74 components for slave and master.

            Fig 3 :- Type7 Contact Creation

4. Check for penetration and intersection by Tools->Penetration Check->Intersection and Penetration->Select all the components->Check.

            Fig 4 :- Penetration Check

If there are any issues with the penetration, then fix them using appropriate commands.

5. Create rigid wall by Solver deck->Right Click->RWall->Plane. Select the outermost node on the bumper and offset towards the X-axis to maintain the gap.

The sliding friction should be 0.1

                     Fig 5.1 :- Create rigid wall

                                          Fig 5.2 :- Rigid Wall Created

6. Check for center of gravity by Tools->Mass Details->Mass, COG and Inertia. Initially mass is around 180Kg and CG is not at the desirable point.

Add mass at appropriate points to get upto 700kg and CG at desirable point.

Solverdeck->Right Click->ADMAS->Select the nodes to add mass->enter mass value.

                                          Fig 6.1 :- Nodes Selection for adding mass

                    Fig 6.2 :- Create GRNOD

               Fig 6.3 :- After mass addition

                                        Fig 6.4 :- Updated COG at desirable point

7. Create a initial velocity card by Solverdeck->Right Click->Create Inivel->Select all the 74 components.

35 mph can also be entered as 15.656 mm/ms to match our unit system.

                 Fig 7 :- Initial Velocity Card

8. Check the quality by Tools->Model Checker->Radioss Block. Run the checker and if there are any issues then auto fix the issue.

9. Set up the time step by going to Model Browser->Cards->Anim_Dt->Tfreq=5.

                        Fig 8 :- Time step 

10. Enter the run timing by Model Browser->Cards->Eng_Run->Tstop=80.

                        Fig 9 :- Run Time

11. Create Sections for the following components by Solver browser->Right click->create->frame->MOV.

                                                                Fig 10.1 :- Creation of Moving Frame card

After creating the moving frame, create sections by Solver browser->right click->create->SECT->SECT. Specify the FRame_ID with the created moving frame, alpha=0.6 and detla=0.1

       Fig 10.2 :- Section Created

Similarly create sections for;

• CBN Outer R
• CBN Outer L
• Shot Gun R
• Shot Gun L
• Fender FT R
• Fender5 FT L
• Headlight Bracket R
• Headlight Bracket L

 

                                                         Fig 10.3 :- All Sections Created

12. Create Intrusions on the Dash board walls 66695 & 66244 as specified.

                                             Fig 11.1 :- Turn on the Node numbers

Create Skew for seat connectors opposite to the dash board walls.

                                             Fig 11.2 :- Creatre Skew for seat connector

Create an Output block by Model browse->Output Block->Right Click->Create. Select the node & skew respectively.

                    Fig 11.3 :- Intrusions Created

13. Run the analysis by Analysis->RADIOSS->Save as 0000.rad->Enter "-nt 4" in options->check incluse connectors->Radioss.

                                                              Fig 12.1 :- Analysis Set up

                                                              Fig 12.2 :- Analysis Completed

                                                                  Fig 12.3 :- Analysis Output

• Energy Error = -1.0%
• Mass Error = 0.3037E-01
• Total Run time = 2480.44 s (41:20 Min)
• Total No. of Cycles = 80001

14. Open Hyperview to view the simulation of crash. Apply the .h3d file from the output generated by simulation.

                                                                                  Displacement After Front Crash

                                                                                  Von Mises Stress After Front Crash

                                                                                       Fig 13.1 :- Energy Plot

15. Cross section forces and their resultant are ploted below,

• CH-CBN-Outer

• Shot Gun

• Fender

• Headlight Bracket

16. The intrusions are also plotted on the graph as shown below,

Intrusion on Node 66695

Intrusion on Node 66244

Result :-

The given vehicle model is simulated for frontal crash using Hypermesh with Radioss solver and the animation, energy plot, intrusion plots are represented above.

As a result, the maximum deformation was noticed in the cabin and the intrusion is minimum on the driver seat.