Development of Detailed AM50%ile Hybrid III Dummy FE Model - - PowerPoint PPT Presentation

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Development of Detailed AM50%ile Hybrid III Dummy FE Model

Presented at LS-DYNA Forum, 13 October 2011, Filderstadt (Stuttgart), Germany TOYOTA MOTOR CORPORATION Tatsuya KOMAMURA

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CONTENTS CONTENTS

• 1. Background and Objectives
• 2. Development of Frontal Impact

Dummy FE Model

• 3. Model Validation
• 4. Discussion
• 5. Conclusions

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1-1． Background

The dummy’s injury measurements are evaluated in FMVSS 208, such as head G, chest deflection and so on. FE analysis recently is utilized to predict the dummy responses. Miyazaki et al. developed a FE flex impactor model using reverse engineering technique with CT scan measurement. Developing a fine dummy FE model with the technique is also expected.

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1-2．Objectives

To develop a HybridⅢ AM50%ile dummy model using the reverse engineering technique. To examine the kinematics and injury responses by comparing to those from the tests.

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2-1．Reverse Engineering

・Fine mesh from the geometry data scanned by X ray CT. ・Input the experimentally measured material properties

and joint stiffness.

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2-2．X-ray CT scan

X-ray CT scanner Sectional points groups 3D geometry (STL)

・Geometry data is obtained with a physical dummy

at 1mm scan pitch by TMC-owned X-ray CT scanner.

・Metal and non-metal 2D images are obtained by

setting X-ray threshold levels.

・3D geometry is obtained by image reconstruction.

〔Example：Torso〕

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2-3．Mesh Generation

FE mesh is made in detail to represent 3D data w/o omission

• Element size: 3-5mm for deformable parts
• Skin parts: Meshed with Solid Element

The number of elements

〔Overview〕 〔Section View〕

Part 320 Node 450,000 ELEMENT 390,000

HybridⅢ AM50%ile FE Model

Skin (Solid) Rib (Shell And& Solid) Spine Box (Solid)

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2-4．Material Properties

Test specimens are taken out of a new physical dummy

• Static tension tests for 49 parts
• Dynamic tension tests for 7 parts such as “Lumber spine”

The No. of Specimens Material

2 Etc. 1 Ensolite 5 Vinyl 8 Rubber 2 Dumping Material 5 Aluminum 26 Steel

The Number of Test Specimens

Total 49

〔例：Lumber Spine〕

Test Machine

Stress [N/mm2] 5 10 15 20 25 30 50 100 150 Strain [% ]

Static Dynamic

5 10 15 20 25 30 35 40 45 Force[N] Frequency[%] 2 3 4 5 6 7 8 9 10 11 1

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2-5． Mechanical Properties

• Joint stiffness is measured at 27 joints
• Ave. value from 90 data obtained at each joint is applied

〔Example〕

Measurement of Shoulder Joint Measurement Result

F Dummy AM50 Push Pull Gauge Shoulder Joint 3 2 m m

Ave.

Assembly Head

Head Drop Test

○

Neck Pendulum Test (+ )

○

Neck Pendulum Test (-)

○

Thorax Impact Test (Low Speed)

○

Rib Static compression Test

○

Thorax Dynamic Seatbelt Test

○ Pelvis

Hip Joint-Femur Flexion Test

○

Knee Impact Test

○

Knee Slide Impact Test

○

Upper Foot Impact Test - without Shoe

○

Lower Foot Impact Test - without Shoe

○

Lower Foot Impact Test - with Shoe

○ Sled All

Full Lap Sled Test

○ Compornent Leg Neck Thorax

Thorax I mpact Test

○ Standard Certification Test Additional Test Knee

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3-1．Model Validation

• 10 certification tests based on FMVSS208 are conducted
• Tests for chest characteristics and sled test are added

Result Result

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3-2．Measurement of Chest Deflection

• Chest deflection is equal to the displacement of

the sternum plate relative to the spine box.

Measurement of Chest Deflection

〔Overview〕 〔Central Section View〕

F d

d: Chest Deflection

Spine Box Rib

Sternum Plate

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3-3．Dynamic Seatbelt Loading

• Seatbelt tension loading on the chest fixed spine rigidly
• 2 tests of different belt path on the chest are evaluated

Test Condition

V V

Comparison of Seatbelt Path

〔Path B〕 〔Path A〕

Fix Fix

Tension velocity is aimed to simulate chest deflection rate in crash tests.

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3-4． Comparison of Internal Kinematics

Simulation Test

• The sternum plate kinematics coincide with the test.

Pass A

0.02 0.04 0.06 0.08 Time [ms] 1.2 1.0 0.8 0.6 0.4 0.2

Ratio

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3-5．Comparison of Chest Deflection

Chest Deflection (Test Max. Value Original Pass= 1.0)

〔Path A〕

Simulation Test

〔Path B〕

Simulation Test Time [sec] Time [sec]

・Chest deflection is well coincide with the test in both

2 path conditions.

8 17 25 33 42 50 0.02 0.04 0.06 0.08 Time [ms] 1.2 1.0 0.8 0.6 0.4 0.2

Ratio

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3-6．Frontal Full Lap Sled Test

Simulation Model

Not Available Instrument Panel Not Available Airbag Available Seatbelt Activated Pretensioner 4 kN Force Limiter Passenger Occupant 48 km/h Impact Velocity

Simulation Condition

・Sled condition: 48km/h Full lap frontal crash ・Restraint system: Seat, Seatbelt with force limiter

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3-7． Comparison of Kinematics

• Kinematics of FE model correlates to test.

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3-8．Comparison of Chest Def.

• Chest deflection of FE model correlate to test data.

Chest Deflection

Acceleration (FE/TEST Max. Value)

80 160 240 320 400 480 Acceleration [m/s

2]

1.2 1.0 0.8 0.6 0.4 0.2

Deflection (FE/TEST Max. Value)

Simulation Test

# 1 # 2

0 0.02 0.04 0.06 0.08 0.1 0.12 Time [sec]

Pretensioner Constant Def. Pelvis Rebound

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4-1．Kinematics

・0～50ms：Translational movement bet. chest and pelvis ・50ms～：Forward movement with rotation in thorax

Displacement of Thorax and Pelvis

0 ms 50 ms 80 ms

50 100 150 200 250 300 0.02 0.04 0.06 0.08 0.1 0.12 Time [sec] Displacement [mm] Thorax Pelvis

Translation Rotation

0.05

＃1 # 2

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② 50 ms ③ 80 ms

・ 50~ 80ms: Acting force on clavicle increases while that

Force on rib keeps constant.

Comparison of Von Mises Stress Comparison of Force

0.0 1.0 2.0 3.0 4.0 5.0 50ms 80ms Ratio (50ms= 1.0) Clavicle Rib Chest Def.

4-2． Acting Force from Belt

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5．Conclusions

(1) Developed a detailed FE HIII Dummy model with reverse engineering using X-ray CT scans. (2) Material properties were studied by cutting out test specimens from dummy component parts and performed static and dynamic tests. (3) The force response of the developed FE model was verified in comparison tests and found to be consistent with the results obtained from a physical dummy. (4) It was concluded that this detailed FE model is effective for analyzing deformation and force transfer inside the dummy in crash tests.

Thank you for your attention.

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