Structural Analysis of Toyota RAV4 using test protocols of National Highway and Traffic Safety Administration (NHTSA) and Insurance Institute for Highway Safety (IIHS) .

1. Structural Analysis of Toyota-RAV4 (1990’s)
and Convertible Version of it using LS-DYNA
explicit-solver
Made by:
Akshay Mistri, Abhishek Ropalkar
Prajakta Chavan, Prathamesh Jambhale
Shreyas Kond, Varun Jadhav
Crashworthiness &
Occupant Protection-I
Winter-2018

2. TEAM DETAILS
Team Member Access ID Dedicated Test
Akshay Mistri (Lead) GF6919 IIHS 40% Offset Moderate Overlap Frontal Impact
Abhishek Ropalkar GJ1469 NHTSA Rigid Pole Side Impact
Prajakta Chavan GK3211 NHTSA Rear Impact
Prathamesh Jambhale GK5894 IIHS 25% Small Offset Frontal Impact
Shreyas Kond GK5348 IIHS Side Impact with Movable Deformable Barrier (MDB)
Varun Jadhav GK0862 NHTSA Full Frontal Impact
2

3. CONTENTS
• Modifications
• Results:
– IIHS 40% Moderate Overlap Frontal Crash Test
– IIHS 25% Small Offset Frontal Crash Test
– NHTSA Full Frontal Crash Test
– IIHS Movable Deformable Barrier Side Impact Crash Test
– NHTSA Side Pole Impact Test
– NHTSA Rear Impact Test
• Future Work
3

4. BASELINE VS CONVERTIBLE
4
Mass : 1.01 Tons
Mass : 1.06 Tons

5. 3D RENDERED MODEL
5

6. 6
MODIFICATIONS - FRAME
BASELINE CONVERTIBLE
Integral Part of Frame

7. MODIFICATIONS – A PILLAR
BASELINE
7
CONVERTIBLE
ROOF RAIL

8. 8
MODIFICATIONS - FLOOR
BASELINE CONVERTIBLE
Aluminium Rail

9. 9
MODIFICATIONS – REAR END
BASELINE CONVERTIBLE
Steel Plate

10. 10
MODIFICATIONS – BOTTOM END
BASELINE CONVERTIBLE
Aluminium Member

11. 11
MODIFICATIONS – REAR END
REAR END ADDITIONS

12. 12
MODIFICATIONS – MORPHED FRONT END

13. IIHS 40% OFFSET MODERATE OVERLAP
FRONTAL CRASH TEST
13

14. TEST DETAILS
• DEFORMABLE
HONEYCOMB
BARRIER.
• 40 % WIDTH STRIKES
THE BARRIER.
• VEHICLE SPEED 40
MPH.
• RATING FACTOR:
DASH INTRUSION.
14

15. MODEL SETUP
15
BASELINE CONVERTIBLE

16. DISPLACEMENT (CRUSH) TIME HISTORY
16
Crush Max Value [mm]
Baseline 1460
Convertible 1510

17. 17
ACCELERATION & VELOCITY TIME HISTORY
Velocity Value [m/sec]
Baseline Max: 17.8
Min: 4.96
Convertible Max: 17.8
Min: 5.96
Acceleration Max Value [g]
Baseline 38.3
Convertible 42.9

18. ACCELERATION PULSE
18
Min Value Max Value
Baseline 23.4 g’s @
0 mm
38.3 g’s @
1459 mm
Convertible 25.6 g’s @
0 mm
42.9 g’s @
1500 mm

19. DASHBOARD INTRUSION
19
Intrusion Max Value
[cm]
Baseline 35.8
Convertible 46.7
• Hence, POOR rating in both cases.

20. FORCE AND INTERNAL ENERGY
20
Energy
Absorbed
Max Value [kJ]
Baseline 145
Convertible 135
Impact Force Max Value [kN]
Baseline 114
Convertible 128

21. CONCLUSIONS
• RATING DEGRADES: LACK OF LOADPATH.
• STRENGTHENING THE FRONT RAIL MATERIALS FURTHER
INCREASES THE INSTRUSION.
• EXCESSIVE CHANGES IN FRONT STRUCTURE NEEDED.
21

22. ANIMATIONS
22
BASELINE CONVERTIBLE

23. IIHS 25% OFFSET SMALL OVERLAP
FRONTAL CRASH TEST
23

24. TEST DETAILS
• 5-foot-tall rigid barrier.
• 25 % WIDTH STRIKES THE
BARRIER.
• VEHICLE SPEED 40 MPH.
• RATING FACTOR:
a) DASH INTRUSION,
b) A- PILLAR & B- PILLAR
INTRUSION (DOOR
INTRUSION).
24

25. MODEL SETUP
25
BASELINE CONVERTIBLE
TOP VIEW

26. DISPLACEMENT (CRUSH) TIME HISTORY
26
Crush Max Value [mm]
Baseline 1800
Convertible 1850

27. 27
ACCELERATION & VELOCITY TIME HISTORY
Velocity Value [m/sec]
Baseline Max: 17.8
Min: 11.0
Convertible Max: 17.8
Min: 10.4
Acceleration Max Value [g]
Baseline 38.3
Convertible 45.5

28. ACCELERATION PULSE
28
Min Value Min Value
Baseline 28.4 g’s @
0 mm
45.3 g’s @
1250 mm
Convertible 23.6 g’s @
0 mm
38.9 g’s @
1250 mm

29. DASHBOARD INTRUSION
29
Intrusion Max Value [cm] Rating
Baseline 17.7 Good
Convertible 32.8 Poor

30. DOOR INTRUSION COMPARISON
30
Baseline
Intrusion
Max Value [cm]
Door
Intrusion
Rating
A-pillar 25
18 Acceptable
B-pillar 7
CONVERTIBLE
Intrusion Max Value [cm]
Door
Intrusion
Rating
A-pillar 42
29 Marginal
B-pillar 11

31. TYPES OF VEHICLE CONVERSIONS STUDIED
31
Convertible with roll-cage structure
Convertible vehicle without roll-cage
and with original materials
Convertible Material Without roll-
cage with improved front rail
material
Original material Yield strength:
240 MPa
Improved Material Yield strength:
310 MPa

32. TYPES OF VEHICLE CONVERSIONS STUDIED
32
Convertible with roll-cage
structure
Convertible vehicle without roll-
cage and with original materials
Convertible Material Without roll-
cage with improved front rail
material

33. INTRUSION STUDY FOR DIFFERENT VEHICLE
CONVERSIONS
33
Intrusion Baseline
Convertible with roll-
cage structure
(mm)
Convertible vehicle
without Roll-cage and
with original materials
(mm)
Convertible Material Without
Roll-cage with improved front
rail material
(mm)
Dash-Board
Intrusion
17.7 24.6 32.8 35.7
Rating for dash
board intrusion
Good Marginal Poor Poor
Door Intrusion 18 23.1 29 33.9
Rating for Door
intrusion Good Marginal Poor Poor

34. Improvements A- Arm Dislocation
• Material properties of A-arm are changed to achieve dislocation of wheel after its impact to the wall.
• New Material used: Baked Hardened steel 240-310 (BH-240-310)
34
Properties
Original
Material
BH 240-310
Yield strength
(MPa)
370 210
Original wheel movement Improved Wheel Movement

35. CONCLUSIONS
• RATING DEGRADES: LACK OF LOADPATH.
• STREGTHENING THE FRONT RAIL MATERAILS FURTHER INCREASES THE INSTRUSION.
• ORIGINAL VEHICLE STRUCTURE IS NOT SUITABLE FOR CONVERTIBLE VEHICLE CONVERSION. EXCESSIVE
CHANGES IN FRONT STRUCTURE NEEDED.
35
Original front structure Required front structure

36. NHTSA FULL FRONTAL CRASH TEST
35 MPH
36

37. 37
SETTING THE MODEL ACCORDING TO THE TEST
REQUIREMENTS
Rigid wall

38. MODEL SETUP
38
CONVERTIBLEBASELINE

39. 39
• FULL RIGID WALL BARRIER
• VEHICLE FULL FRONTAL CRASH (NO OFFSET)
• VEHICLE SPEED 35 MPH
• RATING FACTOR: DASH INTRUSION
CONVERTIBLEBASELINE
REQUIREMENTS

40. DISPLACEMENT (CRUSH) TIME HISTORY
40
Crush Max Value [mm]
Baseline 621
Convertible 501
DUE TO THE MATERIAL
CHANGE AND STRUCTURAL
SABILITY THE TOTAL CRUSH IS
OBSERVED TO BE REDUCED.
HENCE MAKES THE
CONVERTIBLE SAFE THAN THE
BASELINE MODEL.

41. 41
ACCELERATION & VELOCITY TIME HISTORY
Velocity Value [m/sec]
Baseline Max: 15.6
Min: 0.67
Convertible Max: 15.6
Min: 0.47
Acceleration Max Value [g]
Baseline 59.1
Convertible 79.2

42. ACCELERATION PULSE
42
Min Value Max Value
Baseline 40.8 g’s @
0 mm
59.1 g’s @
1459 mm
Convertible 61.1 g’s @
0 mm
79.2 g’s @
1500 mm

43. DASHBOARD INTRUSION
43
Intrusion Max Value
[cm]
Baseline 110
Convertible 51.7

44. 44
ANIMATION
CONVERTIBLEBASELINE

45. IIHS SIDE IMPACT CRASH TEST
45

46. TEST SETUP
• DEFORMABLE
HONEYCOMB
BARRIER.
• BARRIER STRIKES
VEHICLE AT 90
DEGREES FROM SIDE.
• BARRIER SPEED 50
KMPH OR 31 MPH.
• HERE, IRD= 144.8 cm.
46

47. RATING DETAILS
• ONLY STRUCTURAL
SAFETY RATING IS
CONSIDERED
• NO INJURY CRITERIA
AS THERE IS NO
DUMMY
• RATING FACTOR:
B-PILLAR INTRUSION.
(ACTUAL IS DISTANCE
FROM DRIVER SEAT)
47

48. MODEL SETUP
48
BASELINE CONVERTIBLE

49. ANIMATIONS
49
BASELINE CONVERTIBLE

50. DISPLACEMENT (CRUSH) TIME HISTORY
50
Displacement Max Value [mm]
Baseline 1330
Convertible 1600

51. 51
ACCELERATION & VELOCITY TIME HISTORY

52. ACCELERATION PULSE
52

53. B-PILLAR INTRUSION DATA POINTS
53
A
B
C
D
E
F
G
A
B
C
D
Baseline Data Points
Convertible Data Points

54. B-PILLAR INTRUSION
54
Intrusion Max Value
[cm]
Baseline 41.1
Convertible 32.5
• Hence, POOR
rating in both
cases.
Baseline
Convertible

55. CONCLUSIONS
• B-PILLAR INTRUSION IS REDUCED.
• STREGTHENING THE ADDITIONAL CROSS MEMBER RESULTS IN
DEFORMATION OF THE OTHER SIDE.
• EXCESSIVE CHANGES IN THE CROSS MEMBER STRUCTURE NEEDED.
55

56. NHTSA SIDE POLE IMPACT
56

57. TEST DETAILS
• RIGID POLE OF 10 INCHES
RADIUS (254 MM)
• VEHICLE SPEED 20 MPH
(8940.81 MM/S)
• ANGLE BETWEEN VEHICLE
AND RIGID BARRIER 75
DEGREES
• RATING FACTOR – ROCKER
INTRUSION
57

58. MODEL SETUP
58
BASELINE CONVERTIBLE

59. DISPLACEMENT TIME HISTORY
59
Crush Max Value [mm]
Baseline 192
Convertible 170

60. 60
ACCELERATION & VELOCITY TIME HISTORY
Velocity Value [m/sec]
Baseline Max: 6.65
Min: 5.00
Convertible Max: 7.65
Min: 6.50
Acceleration Max Value [g]
Baseline 2.94
Convertible 8.79

61. ACCELERATION PULSE
61
Min Value Max Value
Baseline 8e5 mm/s2
@ 98 mm
8.45e5
mm/s2 @
194 mm
Convertible 1.56e5
mm/s2 @
115 mm
2.8e5 mm/s2
@ 189 mm

62. DASHBOARD INTRUSION
62
Intrusion Max Value
[mm]
Baseline 425
Convertible 273
• Value of crush
has decreased in
the convertible
model
0
50
100
150
200
250
300
350
400
450
0 15 30 45 60 75 90 105 120 135 150
DashIntrusion[mm]
Time [ms]
Dash Intrusion Time History Baseline Intrusion Convertible Intrusion

63. CONCLUSIONS
• CRUSH REDUCES: AS WE HAVE ADDED A MEMBER TO SUPPORT SIDE POLE
IMPACT
• STRENGTHENING OF RODS IN DOOR AND DOOR FRAME NEEDED
• ALSO THE BOTTOM FRAME MATERIAL SHOULD BE STIFFENED
63

64. ANIMATIONS
64
BASELINE CONVERTIBLE

65. REAR IMPACT
FUEL SYSTEM INTEGRITY, FMVSS 301
65

66. • Purpose- reduce post-crash fires that result from fuel
spillage
DEFORMABLE HONEYCOMB BARRIER.
70 % width strikes the MDB, FROM FUEL NECK SIDE
Vehicle speed 50 mph.
TEST DETAILS
70%

67. MODEL SETUP
67
BASELINE
CONVERTIBLE

68. 68
MODIFICATIONS – REAR END
REAR END ADDITIONS
COVER
SUPPORTING MEMBER
COVER MATERIAL SUPPORTING MEMBERS MAT
CASE 1 STEEL ALUMINIUM
CASE 2 ALUMINIUM ALUMINIUM
CASE 3 STEEL STEEL

69. DISPLACEMENT (CRUSH) TIME HISTORY
69
Crush Max Value [mm]
Baseline 891
CASE 1 360
CASE 2 327
CASE3 119

70. CONCLUSIONS
• LACK OF ATTENTION TOWORDS FUEL TANK INTRUSION
• ADDING SUPPORTING MEMBER HELPS TO PROTECT
• EXCESSIVE CHANGES IN REAR STRUCTURE NEEDED.
• ADDITION OF BOTTOM SUPPORTING MEMBER WILL HELP
CONTROL REAR IMPACT
70
BOTTOM RAIL

71. ANIMATIONS
71
BASELINE CONVERTIBLE

72. FUTURE WORK
• New Frontal Rail Design to reduce intrusion level.
• Studying Windshield and A-Pillar structure in convertible vehicle.
• Studying B-Pillar structures in convertible vehicle for Side Impact
protection.
72