22 use of virtual tools for accident reconstructions

7/27/2019 22 Use of Virtual Tools for Accident Reconstructions

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Child Dissemination Workshop, TUB, 30th 31st May 2006

Use of Virtual Tools for Accident

Reconstruction

Gonal Tejera, Applus+IDIADA

Use of Virtual Tools for Accident Reconstruction

Child Dissemination Workshop, TUB, May 2006

CONTENTS

Accident reconstruct ion

Virtual tools

Application within CHILD


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Accident reconstruction



Accident reconstruction

Accident investigation forms the basis for the currenttest procedures for vehicle safety development

ROAD

HomologationLABORATORY

VehiclePerformance

TestProcedures

AccidentResearch

A number of factors make it necessary to periodicallyreview vehicle performance and to provide theappropriate feedback


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Accident Reconstruction

Capabilities

Accident reconstruction can give answers to:

Pre-impact sequences

Impact conditions and effects

Post-impact dynamics

Injury causes



Accident Reconstruction

Requirements

To give correct answers accidentreconstruction needs specific data from:

Scenario: measures, marks, climatology

Vehicles: characteristics, deformations,structural work, restraint systems,contacts

Occupants: injuries, personal data(weight, height, age), state andbehaviour before the accident

Virtual tools can help

study the influence

of these parameters

in the kinematics

and the dynamics of

vehicles andoccupants during the

accident sequences


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Virtual tools



Virtual tools

Many accident reconstruction programsavailable, but not all of them work at the samedepth

Some are animators, others simple calculationsheets. There are also full packages, with

vehicle data, sequence simulators, impactcalculators and animation tools

Examples:

animators: 3DSTUDIO

sheets: REC-TEC, Reconstructor 98

full packages: HVE, EDCRASH, PC-CRASH


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Virtual tools

Animation programs are used to create movies of

the accident sequence. They have no

mathematical model base thus kinetic values are

given and not calculated neither validated

Calculation sheets can provide speed estimations

during pre-collision and post-collision phases.

They do not take into account specific parameters

of the vehicles and results are always

approximated



Virtual tools

Complete packages, such as PC-CRASH or HVE,

use:

Mathematical algorithms for collisions

Differential equations for movements

Separate pre and post-collision sequences

definition

Deformations defined by mathematical

models


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Virtual tools

PC-CRASH is generally accepted by the experts inaccident research to be one of the most complete

software available nowadays

Vehicles database

with specificdynamic parameters

Trajectory

definition, with

profile andfriction

Multiple sequences

for pre and post-collision phases



Virtual tools

PC-CRASH modelsz

y

x

x'

y'z'

xy

z

0

1

2

3

Coordinates system and

dynamic model

1

2

tn

T

N

S

-S

n1

t1 n2

t2

P

Kudlich-Slibar classical

3D collision model and

sliding impact model


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Virtual tools

Validation. Occupant movementVergleich PC-Crash Madymo / UDS Madymo / Realcrash

-25

0

25

50

75

100

125

150

0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0,16 0,18 0,2 0,22 0,24 0,26 0,28 0,3 0,32 0,34 0,36 0,38 0,4

uds headres [m/s]

pcc headres [m/s]

kopf(dsd)

uds_ax [m/s]

PC-CRASH MADYMO

UDS MADYMO

Accident



Virtual tools

Output

PC-CRASH is able to provide:

Pre-impact sequences

Good estimates for EES and v

Post-impact dynamics

Occupant kinematics (linked to MADYMO)


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Events description: The Daewo Matiz (in red) goes into the opposite lane and

after an soft sliding contact against a Fiat Punto (in green), it impacts against

a Toyota Corolla Verso (in blue) which tried to avoid the impact by a left

steering manoeuvre.

Acc ident date: 20.06.2004 Investigator: VSB

Acc ident Reference n: CCN 1164 Origin: IDIADA

1st collision: sliding impact

2nd collision: front-to-lateral impact


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M.AIS

1

2

4

Occupants

Restraint

Seatbelt

Seatbelt

FWD CRS G1

Age

39

38

3

Sex

M

F

M

Mass: 851 kg Max. deformation: 350 mm DeltaV: 44 km/h

FRONTAL IMPACTDAEWOO MATIZ

1

2

3

4

5

Year Model: 2003 CDC: 12FDAW5 EES: 67 km/h

Vehicle n 1

M.AIS

11

Occupants

Restraint

SeatbeltSeatbelt

Age

3535

Sex

MF

Mass: 1420 kg Max. deformation: 130 mm DeltaV: 25 km/h

LATERAL IMPACTTOYOTA COROLLA VERSO

12

3

4

5

Year Model: 2003 CDC: 01RYES2 EES: 32 km/h

Vehicle n 2

X

X

9





Daewoo Matiz Fiat Punto

Side-to-side impact

Sliding collision3D collision

Small v and EES:

Post-impact speed

and direction of both

vehicles nearly not

modified

First collision


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Daewoo Matiz Toyota

Corolla

Front-to-lateral collision

Full impact

3D collision

Significant v and EES:

Post-impact speed

and direction of both

vehicles changed

Second collision




Animation Overview of the accident

2nd collision: case collision


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1st collision2nd collision

View from Corolla View from Matiz

Animation



Physical reconstruction: proposed configuration



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Physical reconstruction: other possibilities

Option 2 Option 3




Physical reconstruction

Option 2

Option 2: chosen option

PC-CRASH can also help

define the parameters for the

physical reconstruction in

order to achieve a

representative laboratory

crash


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Physical reconstruction validation






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Conclusions

Accident reconstruction has become a more

accurate discipline with the generalised utilisation

of virtual tools

Full packages provide the widest capabilities foraccident reconstruction

Within CHILD, PC-CRASH was a very helpful tool

to double-check the test configuration proposed by

the experts


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Child Dissemination Workshop, TUB, 30th 31st May 2006

Thank you very much for your attention!

Gonal Tejera, Applus+IDIADA

[email protected]

+34 977 166 021

22 use of virtual tools for accident reconstructions

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