Taryn Rockwell, SAE Govt/Industry meeting, 2003


SLIDE 1: 
SIDE IMPACT VEHICLE TESTING: DEVELOPMENT OF A LATERAL TEST PROCEDURE FOR CHILD RESTRAINTS

Taryn Rockwell, ACE Systems Technologies, Inc.


SLIDE 2:
BACKGROUND

- TREAD act - Nov. 2000
- Mandated that NHTSA determine whether to
  * apply acaled injury criteria performance levels developed for FMVSS No.208 to CRS covered in FMVSS No.213
  * Include CRS in NCAP crash teats
- In response, NHTSA:
  * issued NPRM to address proposed changes to 213 (docket No.2002-11707-3) - proposed 208 scaled injury performance levels
  * issued ANPRM for child protection in side & rear impact
  * conducted frontal & side NCAP vehicle tests with CRABI 12MO & Hybrid III 3YO in CRS


SLIDE 3:
ONGOING RESEARCH TO ADDRESS ISSUES RAISED IN THE ANPRM
Evaluating real world side impact data
 - CHOP, NASS, FARS, SCI

Evaluating different lateral test procedures for evaluating CRSs
 - ISO, Japan NCAP, Australia, EuroNCAP

Sled Testing
 - countermeasures
 - dummies <Q3 vs. Hybrid III>
 - IARVs

Vehicle testing
 - NCAP and R&D


SLIDE 4:
OBJECTIVES OF THIS RESEARCH

Address some of the issues raised in the ANPRM including:
 - determining child injury mechanisms in side impact vehicle tests
 - compare performance in vehicle tests to that of suggested 90-degree sled tests


SLIDE 5:
VEHICLE SELECTION
8 vehicles selected
 - 5 from list of vehicles to be selected for 2002 SINCAP
 - 3 vehicles piggy-backed to R&D tests with ES-2 dummy

The following considered when selecting vehicles
 - difficulty of correctly positioning rear SID dummy - exempt from side NCAP testing
 - popular models
 - covered various vehicle classes (2-dr pass.cars, 4-dr. pass. cars, SUVs, vans, pickups)
 - vehicle availability

  * did NOT attempt to get cross-sample from vehicle manufacturers



SLIDE 6:
VEHICLE CONFIGURATION

For any one particular vehicle, the following were identical for both outboard rear seating positions:
 - model of CRS
 - CRS orientation
 - CRS belt configuration
 - child dummy


SLIDE 7:
MODEL OF CRS
- SAFETY 1ST FORERUNNER
  * 5-point harness
  * convertible
	- 5-35 lbs rear-facing
	- 22-40 lbs forward-facing
  * equipped with lower anchorages & tether (LATCH)

- EVENFLO ON-MY-WAY
  * 5-point harness
  * rear-facing only (infant seat)
	- 5-20lbs
  * equipped only with tether - not used


SLIDE 8:
CRS BELT CONFIGURATION & ORIENTATION

Safety 1st Forerunner
 - VSB, no tether, RF
 - VSB, tether, FF
 - LATCH, FF
 - Lower anchorages, no tether, RF
Evenflow On-My-Way
 - VSB, no tether, RF


SLIDE 9:
CHILD DUMMY SELECTION & INSTRUMENTATION

- Hybrid III 3YO dummy
- 12MO CRABI dummy
- Equipped with:
  * upper & lower neck load cells
  * tri-axial head, chest, and pelvis accelerometers
  * chest lateral spring potentiometer for 3YO only


SLIDE 10:
SIDE NCAP TEST PROCEDURE [top view diagram of configuration]

MDB
 - 27-degree crabbed angle
 - 62.0 km/h (38.5mph)

Target vehicle
 - positioned at 63-degrees to the line of forward motion
 - stationary
 - impacted on driver's side

Simulates car moving at 55 km/h hitting another car moving at 27 km/h


SLIDE 11:
VIDEO OF CRASH TEST - VEHICLE B (PICKUP)
[still photo only - video removed]


SLIDE 12:
POST-TEST CRS EXAMINATION
Post-test examinations showed:
 - no CRS damaged
 - No plastic (permanent) deformation of lower anchorages in vehicle or connection hooks on CRS
 - all vehicle seat belts intact and without damage


SLIDE 13:
INJURY CRITERIA [table]

injury criterion for 12mo CRABI, 3yo Hybrid III

HIC 15			 390 (CRABI) - 570 (HIII)
3ms Chest clip	 	  50 (CRABI) -  55 (HIII)
chest deflection 	  34 (CRABI) -  34 (HIII)

Nij Intercepts:
	tension		1460 (CRABI) - 2340 (HIII)
	compression	1460 (CRABI) - 2120 (HIII)
	flexion		  43 (CRABI) -   68 (HIII)
	extension	  17 (CRABI) -   30 (HIII)

- Suggested in ANPRM issued to address side impact protection for side impact protection for child occupants - Docket No. 02-12151

- examination of IARVs for side impact dummies only used as a baseline comparison


SLIDE 14:
HEAD INJURY CRITERION [bar chart]



SLIDE 15:
HEAD INJURY CRITERION - VEHICLE E
(4-dr. car)
[still from video (exised)]


SLIDE 16:
INTRUSION - VEHICLE E
(4-dr. car)
[still from video (exised)]
points of intrusion circled on windshield, anchor belts, CRS


SLIDE 17:
INTRUSION AT WINDOW SILL
[graph instrusion in mm/ distance from impact in mm, vehicles A-H]


SLIDE 18:
THORACIC CRITERIA - CHEST ACCELERATION
[bar chart - vehicles A-H, vs. normalized chest accelerationin G's]


SLIDE 19:
INTRUSION - VEHICLE F (4-dr.car)
[still from video (exised)]
dummy's chest at approx. window sill level


SLIDE 20:
INTRUSION AT WINDOW SILL
[graph instrusion in mm/ distance from impact in mm, vehicles A-H]


SLIDE 21:
DUMMY POSITIONING
[graph & tables]
Rankings 1-8
1 = closest to door
8 = farthest away from door


SLIDE 22:
THORACIC CRITERIA - CHEST DEFLECTION
 - 3YO dummy only
  * 3 vehicles - F, G, & H
 - dummy readings normalized to 34mm
 - all recorded injuries well below IARV
  * negligible for far-side dummy
 - highest recorded value: 0.58 - near side dummy in vehicle F


SLIDE 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.)

[Development of Improved Injury Criteria for the Assessment of Child Restraint Systems: - docket no. 2002-11707-18


SLIDE 24:
NECK CRITERIA - Nij
[bar chart]


SLIDE 25:
Nij - FILURE MODES FOR 12MO CRABI
- Diamond formed by Nij intercepts
- My & Fz injury values at time of max. Nij found
- Exceed 1 of 4 modes of neck motion if recorded moment/force combination falls outside diamont


SLIDE 26:
Nij - FAILURE MODES FOR 12MO CRABI
[video still - video exised]
Tension/extension in vehicle C (van)
 - Neck Tension: head up relative to neck *OR* chest down relative to neck
 - Neck extension - chin up, away from sternum, forcing head back


SLIDE 27:
Nij - NECK MOTION FOR 3YO HYBRID III


SLIDE :
SLIDE 27:
Nij - NECK MOTION FOR 3YO HYBRID III
[video stills - videos exised]
ex 1: Tension/Extension in vehicle G (2-dr.car)
ex 2: Tension/Extension in vehicle F (4-dr.car)

 - neck tension: head up relative to neck *OR* chest down relative to neck
 - neck flexion: chind down toward sternum & head curls forward


SLIDE 29:
RESULTANT PELVIS ACCELERATION
[bar chart]


SLIDE 30:
SUMMARY OF INJURY
several vehicles exceeded numerous injury criteria


SLIDE 31:
COMPARISON OF SLED TESTS TO VEHICLE TESTS


SLIDE 32:
SUGGESTED LATERAL SLED TESTS TO BE ADDED TO 213

ANPRM suggested 2 options:

- 90-degree, no rigid wall
  * 20 mph
  * 1/2 sine pulse or upgraded 213 pulse
  * tethered CRS
  * impose 20" head excursion limit

- 90-degree, rigid-wall
  * 15 mph
  * Grand Am pulse - derived from pulse of Pontiac Grand Am when tested both under 214 (15mph w/21g peak accel) & side NCAP 21mph w/26g peak accel) 
  * no head excursion limit necessary


SLIDE 33:
COMPARISON OF 90-DEGREE (NO WALL) TRC SLED TESTS TO SINCAP VEHICLE TESTS
[scatter chart]
Near-side dummy readings for HIC 15 & chest G in sled tests (no wall) much lower than in vehicle tests)


SLIDE 34:
COMPARISON OF 90-DEGREE (NO WALL) TRC SLED TESTS TO SINCAP VEHICLE TESTS
[scatter chart]
Inconclusive whether HIC 15 & chest G readings for far-side dummy in vehicle tests greater than in sled tests (no wall).



SLIDE 35:
COMPARISON OF TRC 90-DEGREE RIGID WALL SLED TESTS TO SINCAP VEHICLE TESTS
- 90-degree Y-acceleration on rear floorpan for five vehicles


SLIDE 36:
COMPARISON OF TRC 90-DEGREE RIGID WALL SLED TESTS TO SINCAP VEHICLE TESTS

Average acceleration curve in y-direction for 5 vehicles (v=17.38mph) vs. pulse for 15mph rigid wall sled test


SLIDE 37:
COMPARISON OF TRC 90-DEGREE RIGID WALL SLED TESTS TO SINCAP VEHICLE TESTS

In general, near-side dummy readings for HIC 15 & chest G in 15mph rigid wall sled tests are similar to readings in SINCAP vehicle tests


SLIDE 38:
PRELIMINARY OBSERVATIONS
Based on limited test series:
- CRSs withstand severity of side impact crash conditions

- Near-side dummy readings generally greater than far-side dummy readings
  [contributors: intrusion & lower anchorage locations - changes relative position of dummy]


SLIDE 39:
PRELIMINARY OBSERVATIONS

Sled tests vs. vehicle tests:
- sled test (no wall)
  * near-side dummy - readings for HIC 15 & chest G much lower than in vehicle tests
  * far-side dummy - inconclusive

- sled test (rigid wall)
  * near-side dummy - readings for HIC 15 & chest G for test at 15mph similar to dummy readings for vehicle tests


SLIDE 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