Recent NHTSA Compatibility Research

Repeatability evaluation for recent compatibility test

procedures

2005 SAE Government / Industry Meeting

LC Barrier Repeatability

• 4 56 kph rigid barrier tests with comparable vehicles

• 2004 Honda Accord– Belted 50th into 8 x 16 LC barrier– Belted 5th into 8 x 16 LC barrier – Belted 95th into NCAP 4 by 9 LC barrier

• 2003 Accord– Belted 50th into MGA 2 by 3 LC barrier

Test Comparison

Test Lab Driver Year Make Model Weight Speed4485 MGA 50th 2003 HONDA ACCORD 1571 55.85145 TRC 5th 2004 HONDA ACCORD 1654 56.55062 TRC 50th 2004 HONDA ACCORD 1624 56.65139 KAR 95th 2004 HONDA ACCORD 1834 56.52

The belted 95th test is considerably heavier than the other 3 tests

Test Load cells AHOF Initial

Stiffness4485 6 443.8 1467.65145 134 436.3 1598.75062 134 414.5 1593.15139 36 410.7 1527.0

Generally tests with the 2x3 barrier are not used for AHOF estimates

Total Force (t)

-700K

-600K

-500K

-400K

-300K

-200K

-100K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

NE

WTO

NS

SECONDS

4485 5139 5145 5062

Only around 60 ms do the heavier and lighter vehicles differ

Initial StiffnessHonda Accord Initial Stiffness5062 = 1593.1 N/mm, from 0 to 287 mm, R2 = 0.9515145 = 1598.7 N/mm, from 0 to 289 mm, R2 = 0.9524485 = 1467.6 N/mm, from 0 to 305 mm, R2 = 0.952

Displacement (mm)0 200 400 600 800

Tota

l For

ce (N

)

0

2e+5

4e+5

6e+5

448550625145

The slope for the Force-deflection profiles repeated well

Acceleration (t)

-40

-35

-30

-25

-20

-15

-10

-5

0

5

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

G'S

SECONDS

4485 5062 5145 5139

Acceleration profiles are similar, but not as consistent as total force

Height of Force (t)

350

400

450

500

550

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10

MIL

LIM

ETE

RS

SECONDS

V5139Ahof.uds V5145AHOF.uds v5062HOF.uds

4 by 9 barrierhas differentHOF(t)

8 by 16 barriers are initially similar,but diverge after 50 ms

MGA 2 Row barrier was not evaluated for HOF(t)

Honda Accord – Row Forces

-200K

-150K

-100K

-50K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Force by RowsTest 5062, 2004 HONDA ACCORD, Rows numbered from Ground

Forc

e (N

)

Time (Seconds)

Row 9 Row 8 Row 7 Row 6 Row 5 Row 4 Row 3 Row 2 Row 1

-150K

-100K

-50K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Force by RowsTest 5145, 2004 HONDA ACCORD, Rows numbered from Ground

Forc

e (N

)

Time (Seconds)

Row 9 Row 8 Row 7 Row 6 Row 5 Row 4 Row 3 Row 2 Row 1

Test 5062, Note the strong impact on Row 1

Test 5145, Note force on Row 3 has increased and Row 1 has decreased

Accord Pit Camera - 5062

Accord - ImpulseImpulse, computed from 4.6 to 97.0 ms

Test 5062, 2004 HONDA ACCORD

Hei

ght (

mm

)

Distance From Center (mm)-800 -600 -400 -200 0 200 400 600 800

200

300

400

500

600

700

800

900

1000

1100

0100200300400500600700800900

1000110012001300140015001600170018001900

2000

Impulse, computed from 4.3 to 99.4 msTest 5145, 2004 HONDA ACCORD

Hei

ght (

mm

)

Distance From Center (mm)-800 -600 -400 -200 0 200 400 600 800

200

300

400

500

600

700

800

900

1000

1100

0125250375500625750875

1000112512501375150016251750187520002125225023752500

Test 5062

Test 5145

Deformation and Intrusion

Intrusion Comparison

-1010

3050

7090

110130

150

LeftFootRest

LeftToepan

CenterToepan

RightToepan

BrakePedal

Left IP Right IP

Intr

usio

n (m

m)

5145 5062

With Fascia

-700

-600

-500

-400

-300

-200

-100

0C1 C2 C3 C4 C5 C6

Location

Def

orm

atio

n (m

m)

5145 Pre-test 5145 Post-test 5062 Pre-test 5062 Post-test

IIHS Acceptablelevel

Only TRC tests had matching measurements

External Deformation matches well except for C6 (right side)

The right side IP measured additional intrusion in test 5062

Repeatability - Observations

• HR tests did not repeat AHOF as well as hoped– Engine impact strongly influenced AHOF– FWDB could reduce this effect

• 4x9 row resolution affected HOF(t)• Initial Stiffness repeated well

– Total force was not affected by LC differences between 4x9, 2x3, and 8x16 barriers.

• Need to measure impact accuracy– European tests have shown impact location can

vary up to 20 mm– Did impact accuracy affect the force distributions?

Impact Accuracy

• IHRA researchers has been monitoring the repeatability / accuracy of vehicle impact point– Pre test vehicle to barrier alignment is recorded using

a sticker on barrier– Pin on vehicle puts a hole in sticker and the X and Y

offset is recorded– Up to 35 mm deviation has been recorded

• NHTSA has just begun to record impact accuracy– Working to incorporate into standardized testing

Impact Accuracy

Camry Test, Center of 75 mm target was aligned with the pin pre-test

Accord Test

Full Width Deformable Barrier Tests

Comparison of Plascore and Cellbond Barrier Faces

Concorde Test Series

1996 Chrysler Concorde

test weight speed Barrier AHOFVertical Accuracy

Corrected AHOF

Interval (ms)

4963 1788 56.4 Rigid 435.1 5-1145251 1788 56.4 Cellbond 449.6 20 429.6 7-1195252 1788 56.2 Plascore 434.2 1 433.2 26-138

• Plascore was low bidder• Cellbond was manufacturer for FWDB development tests• FWDB’s were 1000 mm high• FWDB was mounted 125 mm above the ground• AHOF was corrected by subtracting the vertical offset.• Impact accuracy was not measured for the rigid barrier test

Barrier Deformation

Cellbond

Plascore

Total Force (t)

-600K

-500K

-400K

-300K

-200K

-100K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Total Force

NE

WTO

NS

SECONDS

Rigid Barrier CellBond Plascore

The FWDB tests had similar total force measurements

Concorde CG Acceleration (t)

-70

-60

-50

-40

-30

-20

-10

0

10

20

30

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

G'S

SECONDS

Rigid Cellbond Plascore

Acceleration profiles are noisy, which is common for older vehicles

Height of Force (t)

360

380

400

420

440

460

480

500

0.00 0.02 0.04 0.06 0.08 0.10 0.12

Height of Force, Corrected for Impact Accuracy

MIL

LIM

ETE

RS

SECONDS

Rigid Cellbond Plascore

The HOF(t) are similar after correcting for impact accuracy

Row Forces (Uncorrected)

Plascore Barrier

Cellbond Barrier(19 mm higher impact),Increase force in row 4Less in rows 1 and 2

-250K

-200K

-150K

-100K

-50K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Force by RowsTest 5251, 1996 CHRYSLER CONCORDE, Rows numbered from Ground

Forc

e (N

)

Time (Seconds)

Row 9 Row 8 Row 7 Row 6 Row 5 Row 4 Row 3 Row 2 Row 1

-250K

-200K

-150K

-100K

-50K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Force by RowsTest 5252, 1996 CHRYSLER CONCORDE, Rows numbered from Ground

Forc

e (N

)

Time (Seconds)

Row 9 Row 8 Row 7 Row 6 Row 5 Row 4 Row 3 Row 2 Row 1

Rigid Barrier Row Forces

-400K

-350K

-300K

-250K

-200K

-150K

-100K

-50K

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Force by RowsTest 4963, 1996 CHRYSLER CONCORDE, Rows numbered from Ground

Forc

e (N

)

Time (Seconds)

Row 8 Row 7 Row 6 Row 5 Row 4 Row 3 Row 2 Row 1

The force distribution for the rigid barrier test is much different than either of the FWDB tests

Vehicle-to-Vehicle Repeatability

Full Frontal CollinearDodge Ram 1500 into

Honda Accord

Test Matrix

NHTSA conducted a collinear frontal vehicle-to-vehicle test in which a driver air bag failure occurred in the Accord.

Honda repeated the Ram/Accord frontal test, providing an opportunity to examine the repeatability for this vehicle-to-vehicle test series

Test Year Make Model Speed Weight Width Length5041 2002 DODGE RAM1500 92.5 2527 2018 58055041 2004 HONDA ACCORD 0 1624 1894 48005247 2002 DODGE RAM1500 92.4 2502 2024 58055247 2004 HONDA ACCORD 0 1623 1821 4777

MGA ran both tests under identical conditions. Stationary Accord impacted full frontal collinear.Both vehicle centerlines were aligned.

Ram 1500 Post Test

V5247

V5041

Accord Post Test

V5247

V5041

Acceleration

-35

-30

-25

-20

-15

-10

-5

0

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Comparison of Ram / Honda Tests

G'S

SECONDS

V5041 V5247

-40

-35

-30

-25

-20

-15

-10

-5

0

5

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Comparison of Honda Accleration

G'S

SECONDS

V5041 V5247

Honda Accord(CF = 0.96)

Dodge Ram 1500(CF = 0.95)

Injury Measures

Honda Driver injury measures not compared

tstno Striking Vehcle15 ms HIC Max Nij

Chest Acceleration

Chest Deflection

Left Femur

Right Femur

5041 Ram 1500 255.2 0.321 43.9 14.9 3391 32325247 Ram 1500 286.7 0.297 48.1 17 3891 2259

HondaPass

tstnoStriking Vehcle

15 ms HIC Max Nij

Chest Acceleration

Chest Deflection

Left Femur

Right Femur

5041 Ram 1500 130.8 0.245 36.4 26.6 2916 37455247 Ram 1500 180.2 0.219 34 26.7 3909 4011

Ram Driver

tstno15 ms HIC Max Nij

Chest Acceleration

Chest Deflection

Left Femur

Right Femur

5041 Ram 1500 103.3 0.696 37.8 15.9 2888 74865247 Ram 1500 129.95 0.88 37.3 19.3 4309 2879

RamPass

Bullet Vehicle Deformation

Ram 1500 Top of Bumper

-400

-300

-200

-100

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-test 5247 Pre-test 5247 Post-test

Ram 1500 Bottom of Bumper

-350

-300

-250

-200

-150

-100

-50

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-Test 5247 Pre-test 5247 Post-test

Ram 1500 Front of Hood

-80

-60

-40

-20

0

20

40

C1 C2 C3 C4 C5 C6D

ista

nce

(mm

)

5041 Pre-test 5041 Post-test 5247 Pre-test 5247 Post-test

Ram 1500 Center Grill

-250

-200

-150

-100

-50

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-test 5247 Pre-test 5247 Post-test

Target Vehicle Deformation

Honda Accord, Top of Bumper

-900-800-700-600-500-400-300-200-100

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-test 5247 Pre-Test 5247 Post-test

Honda Accord, Bottom of Bumper

-900-800-700-600-500-400-300-200-100

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-test 5247 Pre-test 5247 Post-test

Honda Accord, Center Grill

-800

-700

-600

-500

-400

-300

-200

-100

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-test 5247 Pre-test 5247 Post-test

Honda Accord, Front Hood

-700

-600

-500

-400

-300

-200

-100

0C1 C2 C3 C4 C5 C6

Dis

tanc

e (m

m)

5041 Pre-test 5041 Post-test 5247 Pre-test 5247 Post-test

Observations

• Vehicle measurements repeated very well• Injury measures for Honda passenger and

Ram driver repeated well• Ram Passenger injury measures did not

repeat– No clear explanation for the difference in Ram

passenger femur or neck loads• External deformation measurements

repeated well– The repeat test did not measure toe pan intrusions