Restraint System & Occupant Simulation Capabilities Systems Performance Department August, 2000

Restraint System & Occupant Simulation Capabilities

Systems Performance Department

August, 2000


• Identify and evaluate restraint system parameters with respect to occupant protection

– Driver, passenger, seat-mounted side, curtain air bags

– Seat belts

– Steering wheels

– Sensors

• Perform mathematical modeling (PAMSAFE & MADYMO)

• Perform dynamic sled tests to evaluate systems

• Provide design direction to application engineering team

Responsibilities - Frontal, Side, Rollover Impact


• Restraint Component Level

– Bag geometry design (shape, volume, coverage)

– Inflator selection (output, slope, multi-stage)

– Seat belt (webbing, load limiting, pretensioner)

– Steering wheel (strength)

– Sensors (fire time)

• Restraint System Level (simulation of crash tests)

– Frontal: FMVSS 208, NCAP, Offset frontal

– Side: FMVSS 214, ECE R95, LINCAP, Pole

– Rollover: FMVSS 208, Screw Ramp, Curb Trip

Systems Performance Process: Use of CAE


System and Testing Program Development ProcessAirbag

Bag shapeand volume

Product integrity testing(static and linearimpactor tests)

Model/correlate staticdeployment and impactor

performance

SYSTEM MODELWITH

VALIDATEDCOMPONENTS

Inflator Belts Wheel Other

MODEL MODEL TEST TEST MODEL TEST

Package andvolume check

Initial tank testsand mass flowcalculations

Tank model

Pendulum orlinear impactor

model

Inflator : Mass flow, T, Gas propertiesBag : Material properties, Fold

Knee Bolster : Force/deflectionSteering column: Force/deflectionSeat : Force/deflection

Webbing, retractor andpretensioner tests

Webbing : StiffnessRetractor: Function characteristicsPretensioner : Function characteristics

Model skeletonand stress tests

Quasi-static(Instron) tests

Wheel : Stiffness function

Quasi-static(Instron) tests

TESTTEST


Restraint System Optimization (50th, Mid, NCAP)

INJURY CRITERIA RESULTS

HIC 347

Chest G’s 44.3 g’s

Chest Comp. 38.9 mm

Left Femur 3624 N

Right Femur 3890 N

Rating 5* (9.71%)


Systems Approach to Restraint Design


Simulation Verification for Different Crash Speeds

Various Crash Pulses for SUV

0

10

20

30

40

50

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14

Time (s)

Ac

ce

lera

tio

n (

g's

)

30mph Barrier

30mph Pole

15mph Barrier


System Correlation

-1000

0

1000

2000

3000

4000

5000

6000

0 50 100 150

Time (msec)

Forc

e (

N)

SimulationBelt Load

Sled BeltLoad

Belt Load

Pelvis Resultant Acceleration

0

200

400

600

800

0 50 100 150

Time (msec)

Acc

ele

rati

on

(m

/s**

2)

SimulationPelvis AccelResultant

Sled PelvisAccelResultant

Head Accel Resultant

0

200

400

600

800

1000

0 50 100 150

Time (msec)

Acc

ele

rati

on

(m

/s**

2)

Simulation HeadAccel Resultant

Sled Head AccelResultant

Chest Accel Resultant

0100200300400500600

0 50 100 150

Time (msec)

Acc

ele

rati

on

(m

/s**

2)

SimulationChest AccelResultant

Sled ChestAccelResultant

Sled Results: HIC=1166 Chest Clip=54.0gModel Results: HIC=1156 Chest Clip=48.4g

• Correlate NCAP Model to NCAP Sled Test with Full Power Inflator


• Coupled 5th Female Driver OOPO ModelDriver Inflator OOP Modeling


Rollover: Occupant Kinematic Assessment


Rollover Curtain Bag


• Kinematic Sequence: Chin on Top of ModuleDriver Inflator OOP Modeling


• Comparison Test vs. SimulationDriver Inflator OOP Modeling


Out of Position Child Simulation

Return to Agenda


Out of Position Child Simulation & Test


MADYMO: Knee Air Bag with an Aluminum Load Distributor

MADYMO: Same Knee Air Bag without a Load Distributor

Inflatable Knee Bolster Modeling


Knee Force DeflectionMADYMO - 30mph Unbelted

Knee Bolster Vs. Knee Air Bag

-9000-8000-7000-6000-5000-4000-3000-2000-1000

010002000

0 0.05 0.1 0.15 0.2 0.25

Deflection (m)

Forc

e (N

)

Left-Bolster Right-Bolster Left-Knee Airbag Right-Knee Airbag


Pelvic AccelerationMADYMO - 30mph Unbelted

Knee Bolster Vs. Knee Airbag

0

100

200

300

400

500

600

700

800

900

1000

0 10 20 30 40 50 60 70 80 90 100 110 120

Time (ms)

Ac

ce

lera

tio

n

(m/s

^2

)

Knee Bolster

Knee Airbag

Pelvic AccelerationMADYMO - 30mph Unbelted


0

100

200

300

400

500

600

700

800

900

1000

0 10 20 30 40 50 60 70 80 90 100 110 120

Time (ms)

Ac

ce

lera

tio

n

(m/s

^2

)

Knee Bolster

Knee Airbag


Chest AccelerationMADYMO - 30mph Unbelted


0

100

200

300

400

500

600

0 10 20 30 40 50 60 70 80 90 100 110 120

Time (ms)

Ac

ce

lera

tio

n

(m/s

^2

)

Knee Bolster

Knee Airbag

Chest AccelerationMADYMO - 30mph Unbelted


0

100

200

300

400

500

600

0 10 20 30 40 50 60 70 80 90 100 110 120

Time (ms)

Ac

ce

lera

tio

n

(m/s

^2

)

Knee Bolster

Knee Airbag


Femur LoadsMADYMO - 30mph Unbelted


0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 10 20 30 40 50 60 70 80 90 100 110 120

Time (ms)

Fo

rce (

N)

Knee Bolste - Left Femurr Knee Bolster - Right Femur Knee Airbag - Left Femur Knee Airbag - Right Femur


Inflatable Knee Bolster Test Comparison

Return to Agenda

Documents

Restraint System & Occupant Simulation Capabilities Systems Performance Department August, 2000