Assignment 6-Frontal Crash Simulation Challenge

A frontal crash is the most common type of crash resulting in fatalities. Major strides have been made in frontal protection, thanks in large part to the crash test program that the National Highway Traffic Safety Administration (NHTSA) began in the late 1970s and the crashworthiness evaluations that IIHS began in 1995.

IIHS conducts three different frontal crash tests: a moderate overlap test (formerly known as the frontal offset test), a driver-side small overlap test and a passenger-side small overlap test.

PROCEDURE:--

STEP 1—CHECK COG POINT

1. Initially changing the CENTRE OF GRAVITY by using CRASH application

2. After changing the units, Import the files in crash.

3. To change the center of gravity go to MASS-BALANCING
4. 
5. View the center of gravity
6. 
7. Initial position of COG is
8. 
9. Now mass should be added in all the passenger seat of 70 kg. To add go to LOAD CASE—ADDED MASS—CREAT NEW—TYPE1
10. 
11. 
12. To select the nodes ADD/REMOVE NODES IN THE GRAPHICAL AREA
13. 
14. After this select the nodes
15. 
16. Hit yes and save the changes
17. Now do the same for all the three remaining seats.
18. After do the same. COG will come on center

STEP 2—PENETRATION CHECK

12. Now save the model and open the same model in Hypermesh
13. Now check for penetration TOOLS—PENETRATION CHECK.
14. 
15. 

STEP 3—CREATING INTERFACE

14. Create TYPE 7 interface using recommended parameters
15. 

STEP 4—CREAT RIGID WALL

15. Go to SOLVER DECK—RIGHTCLICK CHOOSE RWALL—PLANE
16. 

THERE SHOULD BE 5-10MM DISTANCE BETWEEN COMPONENT AND RIGID WALL.

16. FRICTION value should be 0.1

STEP 4—APPLY BOUNDARY CINDITION

17. INITIAL VELOCITY/INIVEL
18. SOLVER BROSER—RIGHTCLICK—BOUNDARY CONDITION—INIVEL
19. 
20. Change the 35mph to mps that will be equals to 15.6
21. 

STEP 5—CREATE SECTION

20. Before section we have to define the moving frame

To define that go to SOLVER DECK—RIGHTCLICK—FRAME—MOVE

WE HAVE TO CREAT FRAME ON

• A PILLAR
• SHORTGUN
• RAIL

ON BOTH SIDE THAT IS LEFT AS WELL RIGHT SIDE. SO THERE WILL BE 6 FRAME

STEP 6—CREAT SECTION FOR THE FRAME

21. To create section go to SOLVERDECK—RIGHTCLICK—SECT—SECT
22. 
23. Define the frame_id & grshel_id
24. 

To create grshell_id right click on that and hit create now choose the elements nearby of the frame

THERE WILL BE 6 SECTION FOR THE 6 FRAME

STEP 7—CREAT ACCELEROMETER

23. To create accelerometer go to SOLVERDECK—RIGHTCLICK—ACCELEROMETER
24. 
25. SPECIGY THE NODE ON THE FLOOR.
26. AND DO IT DAME WAY FOR OTHER SIDE AS WELL
27. 
28. After this we have to assign the sensor to the accelerometer

SOLVERDECK—RIGHCLICK—SENSOR—ACCEL

27. Now define the accelerometer for both side floor
28. 

STEP 8—CREATE INTRUSION

28. To create intrusion go to MESH—CREATE—1D SPRING.

29. Now define the property for the spring component. And assign its component also
30. 

STEP 9—DELETE THE UNSED AND EMPTY FILES FROM CRASH

30. For this go to TOOLS—UNUSED—SELECT AND DELETE.
31. 
32. Also delete the empty card as well
33. 

THIS MEANS THERE IS NO EMPTY AND UNSED CARD IN THE MODEL WHICH MAY CAUSE EEROR

STEP 10—RIUN THE MODEL CHECKER IN CRASH

32. Import the model in crash application.
33. Now go to QUALITY—MODEL CHECKER—RUN
34. 
35. It is best practice to do so that model will be very clean.
36. But there are some genuine warning & those are totally acceptable.
37. 

STEP 11—RUN THE SIMUALTION

36. Import the model in Hypermesh
37. Go to ANALAYSIS—RADIOSS
38. 
39. Specify the location and mention –nt 4 in option
40. 
41. 

STEP 12—DO THE POST PROCESSING

39. Click on result.
40. Import .h3d file the animation

This is the von misses displacement animation

This is the displacement deformation aninmation

41. Import .T01 file to plot the graph
42. Graph of total acceleration force defined both side of the floor. It reaches peak around 6.8 m/s. curves follows the zig zag pattern.

43. Obtained graph of TOTAL RESULTANT FORCE RIGHT-HAND SHORTGUN. It reaches a PEAK at 6.3kN. Curves follow zig zag manner

44. Obtained graph of TOTAL RESULTANT FORCE ON RIGHT-HAND RAIL. It reaches PEAK on 16.56KN. Curve start after some time then increases, reaches peak and then starts decreasing

45. Obtained graph of TOTAL RESULTANT FORCE ON RIGHT-HAND A PILLAR. It reaches PEAK on 6.75 KN. curves follow zig-zag manner and reaches peak after considerable time

46. Obtained graph of TOTAL RESULTANT FORCE ON LEFT-HAND ON RAIL. It reaches PEAK on 35.1 KN. Curve start after small force and reaches peak and then becomes constant

47. Obtained graph of TOTAL RESULTANT FORCE ON LEFT-HAND ON A PILLAR. It reaches PEAK on 35.6 KN. Curve starts after some force and then decreases and follow zig zag manner.

48. Obtained graph of TOTAL RESULTANT FORCE ON LEFT-HAND ON SHORTGUN. It reaches PEAK on 7.9 KN. Cuves follows same pattern as above

49. Obtained axial force of type 7. It reaches peak of 22.51 kn force. Curve first increses to pick and then starts decreasing.

50. Obtained graph for both spring intrusion. Curve is increasing almost linearly and reaches peak on the 45.4 KN force

51. Obtained graph is for TOTAL INTERNAL ENERGY & TOTAL KINETIC ENERGY. Kinetic energy is decreasing and internal energy is increasing. And both forces intersect nearly at 40.6 sec

NOTE:-- ONE THING IS COMMON IN ALL THE GRAPH THAT DEFORMATION TAKES PLACE AFTER SMALL INTERVAL OF TIME AND REACHES PEAK ONCE IT COLLIDES WITH RIGID WALL.

CONCLUSION:--

1) Changed the COG

2) check for penetrartion

3) created new interface

4) created accelerometer on b pillar rocker

5) Assign the initial velocity

6) created type 7 contact at front to obtain axial force

7) created rigid wall

8) Finally plotted the graph with obtained result.