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Comparison of CRS Side Impact Test Results Using by Acceleration Type Sled and Deceleration type SledJASIC / JapanGRSP Inf. Group on Child Restraint SystemsCRS-31-08April 11th , 2012Informal document GRSP-51-38

(51st GRSP, 21 25 May 2012,

agenda item 20)

1I will present the Comparison of CRS Side Impact Test Results Using by Acceleration Type Sled and Deceleration type Sled.Background & PurposeNTSEL (type approval test department in Japan) has the acceleration type sled test system. So it is necessary to compare the CRS side impact sled test results between tested by deceleration type sled system and tested by acceleration type sled test system.

We done CRS side impact sled tests by acceleration type sled test system and confirm to compare the test severity between deceleration sled and acceleration sled.

2The back ground of this research is that the NTSEL, which is the type approval test department in Japan, has the acceleration type sled system, and does not have the deceleration type sled system.So we need to confirm that we can do the CRS side impact sled test by acceleration type sled test system.

We done CRS side impact sled tests by acceleration type sled test system and confirm to compare the test severity between deceleration sled and acceleration sled.

Concept of CRS Side Impact Test Using by Acceleration Type Sled System

Next speak to Concept of CRS Side Impact Test Using by Acceleration Type Sled System

3Parameters of New Side Impact Test

Relative velocity between door and sled Door intrusion

This shows the parameters of side impact test.The relative velocity between sled and door, and door intrusion are the parameters.

4Photos before sled tests

5This shows the photos of sled test initial conditions.

Seat is set on sled on sled and therefore seat can be easily moved.

Video

This shows the video of test.

6Test Concept

In this test concept, door moved with sled and seat moved on sled on sled.Relative velocityIntrusion

This shows the velocity and intrusion time histories.

Time of 0ms is defined when the door is at the end of the seat, defined in regulation.The door velocity is maximum before time is 0ms, and the door velocity keep almost constant till the seat velocity catches up with the door.The seat velocity start increasing almost at time is 0ms.Relative velocity between the door and seat is in corridor.The intrusion is the same with relative displacement of door and seat.And the intrusion is almost 250mm and satisfy the regulation.

7Comparison of Test Results Using by Acceleration Type Sled System and Deceleration Type Sled System

Next speak about the comparison test results.8Tested CRS

CRS ACRS BCRS A is Group I TT CRS and CRS B is Group I SL CRS

This shows tested CRS.We tested 2 types of CRSs.Both CRSs were the Group I CRS.CRS A is TT and CRS B is SL.9Maximum injury Measures (CRS A) Date from TUB and Dorel

This is the comparison of maximum injury measures about CRS A.As for the CRS A, we get the data from TUB and Dorel.Test labs were 5 places, Britax, TUB, IDIADA, Dorel and NTSEL.

10Maximum Injury Measures (CRS A) As for the head injury measures, the test results were almost similar

Date from TUB and Dorel

This shows the deviation to mean and coefficient of variation.As for the head injury measures, coefficient of variation are less than 5%.And deviation to mean are less than 10%.

So as for the maximum head injury measures, the test results were almost similar.11

Video of Side Impact Test (CRS A)Deceleration SledAcceleration SledDate from Dorel

This shows the test videos of CRS A tests used by deceleration sled and acceleration sled.Data was got from Dorel12Relative velocityTime Histories (CRS A)

Date from Dorel

This shows the relative velocity time histories.

13Head accelerationTime Histories (CRS A) As for the head acceleration, time histories were almost similar

Date from Dorel

This shows the head resultant acceleration time histories.Though the timing of start rising of head resultant acceleration was different, the shape and maximum head resultant accelerations were similar.

14Chest accelerationTime Histories (CRS A) Pelvis accelerationNeck Upper ForceNeck Upper Moment

Date from Dorel

This shows chest and pelvis acceleration ,neck force and neck moment.15Head acceleration (Dorel data moves 5ms)Time Histories (CRS A) As for the head acceleration, time histories were almost similar

Date from Dorel

This shows the time history that the time changed.The shape of chest injury measures were almost same.

16Chest accelerationTime Histories (CRS A) Pelvis accelerationNeck Upper ForceNeck Upper MomentDorel data moves 5ms

Date from Dorel

Maximum Injury Measures (CRS B) Date from Dorel

Date from Dorel

This is the comparison of maximum injury measures about CRS B.As for the CRS B, we get the data from Dorel.Test labs were 2 places,, Dorel and NTSEL.

18Maximum Injury Measures (CRS B)

As for the head injury measures, the test results were almost similarDate from Dorel

This shows the deviation to mean and coefficient of variation.As for the head injury measures, coefficient of variation are less than 5%.

So as for the maximum head injury measures, the test results were almost similar.

19Video of Side Impact Test (CRS B)Deceleration Sled

Acceleration SledDate from Dorel

This shows the test videos of CRS B tests used by deceleration sled and acceleration sled.Data was got from Dorel

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Relative velocityTime Histories (CRS B) Date from Dorel

Head accelerationTime Histories (CRS B)

As for the head acceleration, time histories were almost similarDate from Dorel

This shows the head resultant acceleration time histories.The shape and maximum head resultant accelerations were similar.

22Chest accelerationTime Histories (CRS B) Pelvis accelerationNeck Upper ForceNeck Upper Moment0102030405060708001020304050607080Time (ms)Acceleration (G)NTSELDorel010203040506070809010011001020304050607080Time (ms)Acceleration (G)NTSELDorel0100200300400500600700800900100001020304050607080Time (ms)Force (N)NTSELDorel-6-4-20246810121401020304050607080Time (ms)Moment (N m)NTSELDorelDate from Dorel

This shows chest and pelvis acceleration ,neck force and neck moment.The shapes were similar.

23ConclusionAs for the head injury measures, the results used by acceleration sled and deceleration sled were almost similar.

Comparison of Dorel data and NTSEL data, time histories were almost similar.

Severity of the CRS side impact test used by deceleration sled and acceleration sled are similar.

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