1. Vehicle Safety

2. Vehicle Safety Requirements
Side Impact
Frontal Impact – Rigid Barrier
Frontal Offset Impact
Rear impact
Pedestrian Protection
Roof Crush
Seat subsystem
Interior Head Impact
Low Speed Bumper Impact

3. Vehicle Safety Loadcases
FULL-WIDTH FRONTAL
AU/EU/JP/US NCAP
FMVSS 208
FRONTAL OFFSET
AU/EU/JP NCAP
US IIHS
REAR IMPACT
ECE R32
FMVSS 301
SIDE IMPACT
IIHS/JP/AU/EU NCAP
US NCAP
FRONT SEAT
REAR SEAT
FMVSS 214
ECE R95
EU NCAP
SIDE POLE IMPACT
FMVSS 216
ROOF CRUSH
HEAD IMPACT
FREE MOTION HEAD FORM
UPPER LEG
LEG
CHILD HEAD
ADULT HEAD
PEDESTRIAN IMPACT

4. Off-set Frontal Impact
Parameter
Target
HPC
< 1000
Head Resultant Accel.
< 80 G
Residual Steering Column X-Displacement
< 100 mm
Residual Steering Column Z-Displacement
< 80 mm
Neck Injury Criteria
Thorax Compression Criteria
< 50 mm
Viscous Criteria (Thorax)
< 1.0 m/s
Tibia Compression Force
< 8.0 kN
Tibia Index
< 1.3
Sliding Knee joint movement
< 15 mm
Femur Force
No locking of Door lock systems
Door openability
Dummy release and removal
Fuel Leakage
ECE-94 Offset Frontal Impact Regulation
EEVC
ODB
56 kph
Vehicle
2 Hybrid-III Belted Dummies
Test Weight = Kerb Weight + Dummies Weight
Speed = 56 (-0, +1) kph
40% Offset deformable barrier impact

5. Off-set Frontal Impact
Assessments
1. Available Crush space
2. Steering Column Vertical and Rearward Intrusions
2. Dash and Toe-board intrusions
3. Deceleration pulse and Total dynamic crush
4. Major Load paths
5. Energy absorption for key components
6. Fuel Tank damage
7. Front Door aperture deformation
Deformed Shape

6. Off-set Frontal Impact
Baseline Intrusions
Steering Column Intrusions
Toe Pan Intrusions
Brake Booster Location
Toe Board Locations
Hinge Pillar
Steering Column Intrusions Measured at the Wheel Hub Location
Dash Board Intrusions were Higher and Needs Improvement
Steering Column Intrusions Are Meeting the Requirements

7. Off-set Frontal Impact
The Material Grade and Thickness of these components were upgraded to increase the stiffness
Dash and Steering Column intrusions were significantly improved in final version
Peak crash pulse was also within the target level
Counter Measures to reduce Dash intrusion

8. Side Impact ECE-95 Side Impact Regulation Parameter Unit Target 17.3”
9.8”
19.7”
Barrier Side View
Foam material
Front
50 kph (+/- 1)
2094 lbs
Test Weight = Kerb Weight + 1 Dummy Weight
EEVC Moving Deformable Barrier
Target
Vehicle
59”
Centerline at
R-point
Parameter
Unit
Target
HPC (HIC) (If Head contacts) -
< 1000
Rib deflection mm
< 42
Viscous Criteria (Thorax)
m/s
< 1.0
Pubic Symphysis Force kN
</= 6
Abdomen Force
< 2.5
Door openability
Dummy release / removal
Fuel leakage
Internal components

9. Side Impact Analysis Setup Details R Plane : Middle of Barrier 50kph
Center of the Barrier Oriented to R Point Plane of Dummy
Unladen Ground Line Data was Used As Ground
Contact Defined Between Barrier and Occupant Side Vehicle Parts
Distance Between Lower Edge of Honey Comb Barrier to Floor was 300mm
R Plane : Middle of Barrier
50kph
Analysis Setup Details
300mm

10. Side Impact Vehicle Global Deformation B/line H -Point
Collapse of Sill Section at B Post Flange End
H -Point
B/line
Overall Vehicle Deformation Looks Good
B-pillar Intrusion Measured at Belt Line Level Is Lesser Than Intrusion Measured at H Point Level. Overall Deformed Shape of the Pillar Looks Good
Sill Section Below the Slide Door Lower Edge Buckles Close to B-pillar Due to Weaker Sill Section at This Location
B Post Lateral Deformation (Undeformed in Blue)

11. Side Impact Intrusion Measurement on B-post Measurement Points
Top
Beltline
H point
Base
Measurement Points
B-POST Roof Rail Level
B-POST Belt
Line Level
Front View 105ms
(Undeformed in Blue)
Parameter
Intrusion (mm)
B-POST Belt Line Intrusion
-----
B-POST H-point Level Intrusion
B-POST Base Intrusion
B-POST Top Intrusion
B-Post H-Point Level
B-Post Base

12. Roof Crush FMVSS 216 Roof Crush Regulation
Force
Front View
762 mm
Side View
1829 mm
Test Device
Rigid Horizontal Surface
Meet following roof strength criteria:
This standard establishes strength requirements for passenger compartment roof.
Force applied is 1.5 times unloaded vehicle weight in kgs. times 9.8, but should not exceed
22,240 N for passenger cars.
Lower surface of test device must not move more than 127 mm.

13. Roof Crush SPC Constraints 1829mm 762mm 5 deg 25 deg
254 mm (Forward Edge of the Test Device to Forward Most Point of Roof)
25 deg
5 deg
SPC Constraints
Boundary Conditions
Rigid Flat Surface Was Oriented at the Front Driver Side Roof As Shown in the Above Pictures
Prescribed Velocity Was Applied to the Rigid Flat Surface and the Run Was Done Till 125mm Roof Crush
BIW Was Fixed at the Sill Area (for All DoFs) Using Single Point Constraints
Acceptance Criteria
Force Equivalent to 1.5 Times the Unloaded Vehicle Weight or 22,240N, Whichever Is Less Should Be Applied on the Vehicle Roof Structure Using the Rigid Flat Test Device As Per FMVSS 216 Test Setup
The Lower Surface of the Test Device Must Not Move More Than 125mm for This Load

14. Roof Crush B-Pillar Front View Left View
The Model Is Meeting the Roof Crush Resistance As Required by FMVSS 216
B-pillar Buckles at the Belt Line Location

15. Pedestrian Protection
Euro-NCAP Pedestrian Impact
Criteria Measured
UPPER LEG
LEG
CHILD HEAD
ADULT HEAD
Body Form Impactor
Injury Criteria
Limit
Legform
Knee Bending Angle
15 deg
Knee Shear Displacement
6 mm
Upper Tibia Acceleration
150 g
Upper Legform
Sum of Impact Forces
5 kN
Bending moment
300 N-m
Child Headform
Head Injury Criteria
1000
Adult Headform

16. Pedestrian Protection
Initial Velocity
Lower Leg Consisted of TIBIA and FEMUR Joined at Knee
Initial Velocity Assigned to Leg Form and Set as Free Flight
Vehicle Front end Model was Constrained at Rear
Leg Impact was Done with 42 KMPH Initial Velocity
TIBIA Acceleration, Knee Shear and Knee Bending Calculated for Each Case
Foam and Facia Modified During the Iterative Process

17. Pedestrian Protection
Bumper System Met the Knee Injury Criteria as Required by EEVC
Force on Bumper Sensor was Maximum and Consistent Irrespective of Position of Impact
Equivalent Impactors Developed for Pedestrian Dummies

18. Roof Side Rail between A/B Pillars Roof Side Rail between B/C Pillars
Head Impact
FMVSS 201U - Interior Head Impact
Criteria Measured
HEAD IMPACT
FMVSS 201U
FREE MOTION HEAD FORM
Velocity = 15 mph
HIC < 10000
Impact Locations
A-Pillar Lower
A-Pillar Mid
A-Pillar Joint
Windshield Header
Visor Attachment
Roof Side Rail between A/B Pillars
B-Piller Lower
B-Pillar Mid
B-Pillar Joint
Roof Side Rail between B/C Pillars
C-Pillar Joint
Rear Header
Upper Roof
Moon roof Frame

19. Head Impact
Head Impact Simulation

20. Head Impact Hit on Roof Above C-Pillar (Roofc)
Hit on Roof Above B-pillar (Roofb)
Hit on Sun Roof Guide Rail
Hit on Grab Handle

21. Head Impact Honeycomb Countermeasure Roof Bow C-Pillar Headliner
Design Issues:
Does Not Meet HIC Requirement at Various Location
Space Between Headliner and Roof Not Sufficient for Any Countermeasure
Design Solutions:
Headliner Contour Changed to Create Space Between Headliner and Roof Bow
Honeycomb Countermeasure Added to Meet HIC Requirement
Roof Bow
C-Pillar
Headliner
Honeycomb Countermeasure

22. Example: Counter Measure
Head Impact
Example: Counter Measure
Honeycomb Piece as
Counter Measure
Several Honeycomb Density Evaluated
Several Thickness Evaluated
Other Counter Measures Evaluated
Cost Effective Solution Provided

23. Frontal Impact Passenger Compartment Barrier Engine Compartment Impact
Speed
Body Rail
Front
Clearance
Dash
Clearance

24. Frontal Impact Initial Kinetic Energy = ½ M V 2
Final Kinetic Energy = 0 as vehicle comes to a stop
Initial Kinetic Energy is absorbed by deforming body rail
Collision impact duration is less than 100 ms, hence
Resulting deceleration is quite large G

25. Frontal Impact Absorbed Impact Energy Yield Stress σy Rail Load
Failure Stress σf
Rail Load
Stress σ
Failure
Strain εf
Strain ε
Rail Crush
Front
Clearance
Material Stress-Strain Curve
Rail Load = σ* A
Rail Crush = ε* L
Where A is the cross-sectional area of the rail
L is the length of the rail

26. Frontal Impact Assignment: Assume impact speed of 50 kph
Pick any material for the rail and find stress/strain curve
Assume length of the rail based on vehicle dimensions
Calculate required rail section area and design a section
Show that initial K.E. = energy absorbed by the rail