information for the flexible pedestrian legform impactor (flex-pli)

Information for the Flexible Pedestrian Legform Impactor

(Flex-PLI)

Ministry of Land, Infrastructure and Transport Government of Japan

(J-MLIT)

Informal Document No. GRSP-36-2(36th GRSP, 7-10 December 2004, agenda item A.1.)

Construction

Thigh(RIGID)

Leg (RIGID)

Damper

KneeJoint

(Steel KneeBending Plate)

TRL-LFI Flex-PLI 2003

Thigh(FLEXIBLE)

Leg (FLEXIBLE)

Knee Joint*(ligament restraint

system)

Biofidelity Evaluation

-100

0

100

200

300

400

500

600

0 10 20 30 40 50 60

Deflection (mm)

Mom

ent

(Nm

)

Corridor Lower

Corridor Upper

Corridor Avg.

FlexPLI 2003R Avg.

UVA Mid-Thigh Dynamic Bending Corridor

DDV/DCV Rating0.30 0 to 1 Excellent

1 to 2 Good2 to 3 Moderateover 3 Poor

-50

0

50

100

150

200

250

300

350

400

0 10 20 30 40 50

Deflection (mm)

Mom

ent (

Nm

)

Corridor Lower

Corridor Upper

Corridor Avg.

FlexPLI 2003R Avg.

UVA Mid-Leg Dynamic Bending Corridor

DDV/DCV Rating0.33 0 to 1 Excellent

1 to 2 Good2 to 3 Moderateover 3 Poor

0

20

40

60

80

100

120

140

160

180

200

0 2 4 6 8 10 12 14 16

Angle (deg.)

Mo

me

nt

(Nm

)

Corridor Lower

Corridor Upper

Corridor Avg.

FlexPLI 2003R Avg.

UVA Knee Dynamic Bending Corridor

RatingDDV/DCV 0 to 1 Excellent

1.27 1 to 2 Good2 to 3 Moderateover 3 Poor

Flex-PLI has higher biofidelic construction than the TRL-LFI

Kinematics

Flex-PLI Human FE-Model (THUMS)

TRL-LFI FE-Model of TRL-LFI

JASIC 2003 Report

Flex-PLI can simulate human lower extremity bending motion properly.

Knee bending only

Over all lower extremity bending motion is observed.

Measurement System

for Knee ligamentsinjury assessment

(Angle, Disp.)

for Leg injuryassessment

(Acc.)

Knee Shearing(displacement)

Knee Bending(angle)

Leg 0(acceleration)

TRL-LFI

Knee Joint

65 mm

Impact

for Leg Injury assessment

(strain)

for Knee ligamentsinjury assessment

(Elongation)PCL (elongation)

MCL (elongation)

ACL (elongation)

LCL (elongation)

Flex-PLI 2003

Leg 1 (strain)

Leg 2 (strain)

Leg 3(strain)

Leg 4(strain)

Leg 5 (strain)

Thigh 1 (strain)

Thigh 2 (strain)

Thigh 3 (strain)

Thigh 4 (strain)

Knee Joint

92 mm

172 mm

252 mm

332 mm

93 mm

173 mm

253 mm

333 mm

413 mm

Lateral and Medial Condyle (force)

Impact

Flex-PLI has higher injury assessment ability than the TRL-LFI

no measurement(cannot detect injury)

Discussion

Flex-PLI

TRL-LFI

Knee bending only

Over all lower extremity bending motion is observed.

Biofidelity IssueTRL-LFI has a high possibility to mislead the protection way for the pedestrian lower extremity, since it cannot simulate the human lower extremity motion properly.

Measurement System Issue

TRL-LFI has a high possibility to mislead the protection way for the pedestrian lower extremity, since it doesn’t have a measurement system for the injury assessment of the lower part of the leg.

for Knee ligamentsinjury assessment

(Angle, Disp.)

for Leg injuryassessment

(Acc.)

Knee Shearing(displacement)

Knee Bending(angle)

Leg 0(acceleration)

TRL-LFI

Knee Joint

65 mm

Impact

TRL-LF cannot detect the lower part of the leg severity

no measurement(cannot detect injury)

Conclusions

• Flex-PLI has high biofidelity higher injury assessment ability than the TRL-LFI

• J-MLIT recommends to utilize the Flex-PLI as a tool for GTR/PS legform test.

• However, because of the lack of experience in using the Flex-PLI as a certification tool, a further confirmation process is needed.

Conclusions

Thank you for your attention!