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

11

Video of Crash Test – Vehicle B (Pickup)

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

15

Head Injury Criterion – Vehicle E (4-dr. car)

16

Intrusion – Vehicle E (4-dr. car)

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

19

Intrusion – Vehicle F (4-dr. car)

Dummy’s chest at approx. window sill level

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

31

Comparison of Sled Tests to Vehicle Tests

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

40

Next Steps

Evaluation of countermeasures

Evaluation of biofidelity of dummies for side impact

Additional vehicle testing

Possible development of lateral impact test procedure for CRS