Post on 06-Jun-2018
Side Impact Vehicle Testing: Development of A Lateral Test Procedure for
Child Restraints
Taryn Rockwell, ACE Systems Technologies, Inc.
2
BackgroundTREAD Act – Nov. 2000Mandated that NHTSA determine whether to:l Apply scaled injury criteria performance levels
developed for FMVSS No. 208, to CRS covered in FMVSS No. 213
l Include CRS in NCAP crash tests
In response, NHTSA:l Issued NPRM to address proposed changes to 213
(Docket No. 2002-11707-3) – proposed 208 scaled injury performance levels
l Issued ANPRM for child protection in side & rear impact
l Conducted frontal & side NCAP vehicle tests with CRABI 12MO & Hybrid III 3YO in CRS
3
Ongoing Research to Address Issues Raised in the ANPRM
Evaluating real world side impact datal CHOP, NASS, FARS, SCI
Evaluating different lateral test procedures for evaluating CRSsl ISO, Japan NCAP, Australia, Euro NCAP
Sled testingl Countermeasuresl Dummies
l Q3 vs. Hybrid III
l IARVs
Vehicle testingl NCAP and R&D
4
Objectives of This Research
Address some of the issues raised in the ANPRM including:l Determining child injury mechanisms in side
impact vehicle tests
l Compare performance in vehicle tests to that of suggested 90o sled tests
5
Vehicle Selection
8 vehicles selected:l 5 from list of vehicles to be selected for 2002 SINCAP
l 3 vehicles piggy-backed to R&D tests with ES-2 dummy
The following considered when selecting vehicles:l Difficulty of correctly positioning rear SID dummy –
exempt from side NCAP testing
l Popular models
l Covered various vehicle classes (2-dr. pass. cars, 4-dr. pass. cars, SUVs, vans, pickups)
l Vehicle availability* Did NOT attempt to get cross-sample from vehicle
manufacturers
6
Vehicle Configuration
For any one particular vehicle, the following were identical for both outboard rear seating positions:l Model of CRS
l CRS orientation
l CRS belt configuration
l Child dummy
7
Model of CRSSafety 1st Forerunnerl 5-point harnessl Convertible
l 5-35 lbs. rear-facingl 22-40 lbs. forward-facing
l Equipped with lower anchorages & tether (LATCH)
Evenflo On-My-Wayl 5-point harnessl Rear-facing only (Infant seat)
l 5-20 lbs.
l Equipped only with tether – not used
8
CRS Belt Configuration & Orientation
Safety 1st Forerunnerl VSB, no tether, RF
l VSB, tether, FF
l LATCH, FF
l Lower anchorages, no tether, RF
Evenflo On-My-Wayl VSB, no tether, RF
9
Child Dummy Selection & Instrumentation
Hybrid III 3YO dummy
12MO CRABI dummy
Equipped with:l Upper & lower neck load cells
l Tri-axial head, chest, and pelvis accelerometers
l Chest lateral spring potentiometer for 3YO only
10
Side NCAP Test Procedure
MDBl 27o crabbed anglel 62.0 km/h (38.5 mph)
Target vehiclel Positioned at 63o to the
line of forward motion
l Stationaryl Impacted on driver’s side
Simulates car moving at 55 km/h hitting another car moving at 27 km/h
12
Post-Test CRS Examination
Post-test examinations showed:l No CRS damaged
l No plastic (permanent) deformation of lower anchorages in vehicle or connection hooks on CRS
l All vehicle seat belts intact and without damage
13
Injury Criteria
Suggested in ANPRM issued to address side impact protection for child occupants – Docket No. 02-12151Examination of IARVs for side impact dummies only used as a baseline comparison
3017Extension
6843Flexion
21201460Compression
23401460Nij Intercepts: Tension
3434Chest Deflection
55503 ms Chest Clip
570390HIC 15
3YO Hybrid III12MO CRABIINJURY CRITERION
14
Head Injury Criterion
12MO
RF
NL
Pickup
3YO
FF
L
4-dr car
3YO3YO12MO12MO12MO12MO
SUV2-dr car4-dr car4-dr carVanPickup
FFFFFFRFRFRF
NLLLLLNL
0 .0
0 .2
0 .4
0 .6
0 .8
1 .0
1 .2
1 .4
1 .6
1 .8
2 .0
No
rmal
ized
HIC
15
A B C D E F G H
V e h i c l e s
Head In ju ry Cr i t e r ion 15 mi l l i seconds (H IC 15 )
N e a r - S i d e
Fa r -S ide
*4 .42 - Va lue o f f cha r t
17
Intrusion at Window SillVehicle Intrusion at Window Sill
-200
-100
0
100
200
300
400
-1500 -1000 -500 0 500 1000 1500 2000 2500 3000 3500
Distance From Impact (mm)
Intr
usi
on
(mm
)
AB
CDEF
GH
18
Thoracic Criteria – Chest Acceleration
0 .0
0 .5
1 .0
1 .5
2 .0
2 .5
No
rmal
ized
Ch
est
Acc
eler
atio
n (
G's
)
A B C D E F H
V e h i c l e s
C h e s t A c c e l e r a t i o n
N e a r - S i d e
Fa r -S ide
12MO
RF
NL
Pickup
3YO
FF
L
4-dr car
3YO12MO12MO12MO12MO
SUV4-dr car4-dr carVanPickup
FFFFRFRFRF
NLLLLNL
20
Intrusion at Window SillVehicle Intrusion at Window Sill
-200
-100
0
100
200
300
400
-1500 -1000 -500 0 500 1000 1500 2000 2500 3000 3500
Distance From Impact (mm)
Intr
usi
on
(mm
)
AB
CDEF
GH
21
Dummy Positioning
C
B
G
A
H
D
E
F
Van
Pickup
2-dr. car
Pickup
SUV
4-dr. car
4-dr. car
4-dr. car
Child Dummy Closer to Door
Rankings 1-8
1 = closest to door
8 = farthest away from door
20
21
5
7
12
32
27
20
Total
4
6
1
2
3
8
7
4
Ranking
2221E
1112F
6645G
4457H
3333D
8888C
7776B
5564A
HDADCDHSVehicle
22
Thoracic Criteria – Chest Deflection
3YO dummy onlyl 3 vehicles – F, G, & H
Dummy readings normalized to 34 mm
All recorded injuries well below IARVl Negligible for far-side dummy
Highest recorded value: 0.58 – near-side dummy in vehicle F
23
Neck Criteria - Nij
• Faxial = Fz
• Fcritical = Max. force in z-direction (tens./comp.)
• Moc = My + (correction factor)Fx
• Mcritical = Max. moment about y-axis (flex./ext.)
Nij = max[Faxial/Fcritical + Moc/Mcritical]
* “Development of Improved Injury Criteria for the Assessment of Child Restraint Systems.” – Docket No. 2002-11707-18
-3068-212023403YO
-1743-1460146012MO
Extension (N-m)
Flexion (N-m)
Compression (N)
Tension (N)
Dummy
IN-POSITION LIMITS - Nij INTERCEPTS
24
Neck Criteria - Nij
0 .0
0 .2
0 .4
0 .6
0 .8
1 .0
1 .2
1 .4
1 .6
1 .8
Max
imu
m N
ij
A B C D E F G H
V e h i c l e s
M a x i m u m N i j
N e a r - S i d e
Fa r -S ide
12MO
RF
NL
Pickup
3YO
FF
L
4-dr car
3YO3YO12MO12MO12MO12MO
SUV2-dr car4-dr car4-dr carVanPickup
FFFFFFRFRFRF
NLLLLLNL
25
Nij – Failure Modes for 12MO CRABIMaximum Nij Moment and Force Levels for Near Side and Far Side
12-Month-Old CRABI Dummies in Side NCAP CRS Tests
-2500
-2000
-1500
-1000
-500
0
500
1000
1500
2000
2500
-40 -30 -20 -10 0 10 20 30 40 50 60
Moment (N-m)
Fo
rce
(N)
Near Side Dummy
Far Side Dummy
Tension-Flexion
Compression-FlexionCompression-Extension
Tension-Extension
Diamond formed by Nij interceptsMy & Fz injury values at time of max. Nij found
Exceed 1 of 4 modes of neck motion if recorded moment/force combination falls outside diamond
EDCBA
12MO
RF
NL
Pickup
12MO12MO12MO12MO
4-dr car4-dr carVanPickup
FFRFRFRF
LLLNL
26
Nij – Failure Modes for 12MO CRABI
Tension/ Extension in vehicle C (van)
Neck tension – head up relative to neck or chest down relative to neckNeck extension – chin up, away from sternum, forcing head back
27
Nij – Neck Motion for 3YO Hybrid III
Maximum Nij Moment and Force Levels for Near Side and Far Side 3-Year-Old Hybrid III Dummies in Side NCAP CRS Tests
-2500
-2000
-1500
-1000
-500
0
500
1000
1500
2000
2500
-40 -20 0 20 40 60 80
Moment (N-m)
Fo
rce
(N)
Near Side Dummy
Far Side DummyTension-Flexion
Compression-FlexionCompression-Extension
Tension-Extension
Vehicle F
HGF
3YO
FF
L
4-dr car
3YO3YO
SUV2-dr car
FFFF
NLL
28
Nij – Neck Motion for 3YO Hybrid III
Tension/Extension in vehicle G (2-dr. car)
Tension/ Flexion in vehicle F (4-dr. car)
Neck tension – head up relative to neck or chest down relative to neckNeck flexion – chin down toward sternum & head curls forward
29
Resultant Pelvis Acceleration
0
20
40
60
80
1 0 0
1 2 0
1 4 0
1 6 0
Res
ult
ant
Pel
vis
Acc
eler
atio
n (
G's
)
A B C D E F G H
V e h i c l e s
Resu l tan t Pe lv is Acce le ra t ion
N e a r - S i d e
Fa r -S ide
12MO
RF
L
4-dr car
12MO
RF
L
Van
12MO
RF
NL
Pickup
3YO
FF
L
4-dr car
3YO3YO12MO12MO
SUV2-dr car4-dr carPickup
FFFFFFRF
NLLLNL
30
Summary of Injury
Several vehicles exceeded numerous injury criteria
3YO
3YO
3YO
12MO
12MO
12MO
12MO
12MO
Dummy Type
0.470.840.14Near-SideSUVH0.350.470.05Far-Side
0.84N/A0.55Near-Side2-dr. carG0.70N/A0.66Far-Side
0.601.520.53Near-Side4-dr. carF0.470.410.10Far-Side
1.601.881.74Near-Side4-dr. carE0.850.710.56Far-Side
0.972.074.42Near-Side4-dr. carD1.330.731.04Far-Side
1.63N/A0.45Near-SideVanC0.600.330.14Far-Side
1.290.770.28Near-SidePickupA0.550.470.09Far-Side
Pickup
Vehicle Type
Far-Side
Near-Side
Dummy Position
1.000.460.11
0.76N/A0.18B
NijChest G’s
HIC 15
32
Suggested Lateral Sled Tests to Be Added to 213
ANPRM suggested 2 Options:l 90o, no rigid wall
l 20 mphl ½ sine pulse or upgraded 213 pulse
l Tethered CRSl Impose 20” head excursion limit
l 90o, rigid-walll 15 mph
l Grand Am pulse – derived from pulse of Pontiac Grand Am when tested both under 214 (15 mph w/ 21g peakaccel.) & side NCAP (21 mph w/ 26 g peak accel.)
l No head excursion limit necessary
33
Comparison of 90o (No wall) TRC Sled Tests to SINCAP Vehicle Tests
Near-side dummy readings for HIC 15 & chest G in sled tests (no wall) much lower than in vehicle tests
Head & Chest Injury for Near-Side Dummies - Side NCAP Tests Vs. TRC 90o Sled Tests (No Wall)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.0 0.5 1.0 1.5 2.0 2.5
Normalized Chest G
No
rmal
ized
HIC
15
TRC 1/2 Sine Pulse (3YO)
TRC 213 Pulse (3YO)
SINCAP (3YO)
SINCAP (12MO)
34
Comparison of 90o (No wall) TRC Sled Tests to SINCAP Vehicle Tests
Inconclusive whether HIC 15 & chest G readings for far-side dummy in vehicle tests greater than in sled tests (no wall)
Head & Chest Injury for Far-Side Dummies - Side NCAP Tests Vs. TRC 90o Sled Tests (No wall)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Normalized Chest G
No
rmal
ized
HIC
15
TRC 1/2 Sine Pulse (12MO)
TRC 213 Pulse (12MO)
SINCAP (3YO)
SINCAP (12MO)
35
Comparison of TRC 90o Rigid Wall Sled Tests to SINCAP Vehicle Tests
90o Y-acceleration on rear floorpan for five vehicles
-10
-5
0
5
10
15
20
25
30
35
-0.02 -0.01 -0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
Right Rear Floorpan 90 degrees (Y)
G'S
Time in Seconds
RSX Impreza Wagon Santa Fe Sentra TundraG (2-dr. car) F (4-dr. car) H (SUV) E (4-dr. car) A (Pickup)
36
Average acceleration curve in y-direction for 5 vehicles (�v = 17.38 mph) vs. pulse for 15 mph rigid wall sled test
Comparison of TRC 90o Rigid Wall Sled Tests to SINCAP Vehicle Tests
-5
0
5
10
15
20
25
30
-0.02 -0.01 -0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
G'S
Time in Seconds
VRTC 15 mph Rigid Wall Sled Test Pulse Avg. Accel. from Rear Floorpan of SINCAP Tests
~ 0.01 sec.
~ 8 G’s
Note different shape
37
Comparison of TRC 90o Rigid Wall Sled Tests to SINCAP Vehicle Tests
In general, near-side dummy readings for HIC 15 & chest G in 15 mph rigid wall sled tests are similar to readings in SINCAP vehicle tests
Head & Chest Injury for Near-Side Dummies - Side NCAP Tests Vs. TRC 90o Rigid Wall Sled Tests at Various Speeds
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0.0 0.5 1.0 1.5 2.0 2.5
Normalized Chest G
No
rmal
ized
HIC
15
TRC (10 mph)
TRC (15 mph)
TRC (20 mph)
SINCAP (17.4 mph)
38
Preliminary Observations
Based on limited test series:l CRSs withstand severity of side impact crash
conditions
l Near-side dummy readings generally greater than far-side dummy readingsl Contributors: Intrusion & lower anchorage locations –
changes relative position of dummy
39
Preliminary Observations
Sled tests vs. vehicle tests:l Sled test (no wall)
l Near-side dummy - readings for HIC 15 & chest G much lower than in vehicle tests
l Far-side dummy – inconclusive
l Sled test (rigid wall)l Near-side dummy – readings for HIC 15 & chest
G for test at 15 mph similar to dummy readings for vehicle tests