A design approach for lightweight construction of a car body with an example on the micro-car “ec2go”

Fachhochschule Aachen

Fachbereich Luft- und Raumfahrttechnik

A design approach for lightweight construction of a car body with an example on the micro-car “ec2go”

Lehr- und Forschungsgebiet Karosserietechnik

M.Sc. Anuja Nagle / FH Aachen

Prof. Dr.-Ing. T. Roeth / Imperia GmbH

6th European Altair Technology Conference23rd und 24th April 2013 | Turin, Italy

© FH AACHEN UNIVERSITY OF APPLIED SCIENCES 23. April 2013 | 2

Contents


� Introduction

� Micro-Car ec2go

� Flexbody Concept

� Intelligent Car Body (ICB) Approach

� Development of Structural Knowledgebase

� Outlook


Contents

� Introduction

� Micro-Car ec2go




� Outlook



Motivation

Importance of small sized vehicle batch production

� High demands for vehicle derivatives

� Green energy � Increasing need for vehicles with

alternate drives eg. Electric vehicles

Challenges of small series vehicle production

� Restricted knowledge for design

� High development time

� High development costs

� High capital investment

� Fast launching in market

ICB



Partners

Research Partners

Industry Partners

Research Partners

Industry Partners

FB Luft- und RaumfahrttecnikFB EnergietechnikFB GestaltungFB Elektrotechnik und

InformationstechnikFB Maschinenbau und

MechatronikSIJ Solar-Institut Jülich

Supported by



Contents

� Introduction

� Micro-Car ec2go




� Outlook



The Micro-Car ec2go

� Developed as an integral part of a mobility concept

� 2,5m (smaller than Smart)!

� Offers place for 3 people (1+2-Seater)

� Transperent panorama view

� Cross parking possilble



Contents

� Introduction

� Micro-Car ec2go




� Outlook



Flexbody Construction Concept

Geom

etr

yM

anufa

ctu

ring

Str

uctu

re

Knowledgebase

Topology

Profiles

Joints

Car body structure

urb-e (Source: Imperia GmbH)

Lampo3 (Source: ProtoScar)



Flexbody Material Concept

� Combination of different materials possible

� Selection of materials to achieve high level of structural performance andlight weight design

„Das richtige Material an der richtigen Stelle!“



Contents

� Introduction

� Micro-Car ec2go




� Outlook



Manufacturing Intelligence

Intelligent Car Body (ICB) Approach

Virtual ValidationVirtual Validation

Lampo3

Source: Protoscar / TK-SE / Imperia GmbH

ec2go e-car-sharing

Source: FH Aachen

Vehicle Base InformationVehicle Base Information

Attribute ConfiguratorAttribute Configurator

Topology ConfiguratorTopology Configurator

Section ConfiguratorSection Configurator

Joint ConfiguratorJoint Configurator

ConventionalCAE Methods

Geometrical Intelligence Structural Intelligence

Deformation ConfiguratorDeformation Configurator

Level of“I

nte

llig

ence”



Fields of Intelligence in ICB

For parametric CAD construction

Ste

p1:

Topolo

gy

Ste

p2:

Pro

file

sSte

p3:

Join

ts

For selection of materials and manufacturing processes

For optimum design of profile cross sections

Semi-empirical evaluation

Load

dis

trib

ution

Pro

file

sele

ction

Pro

file

D

ata

base

Join

t D

ata

base

Geometrical Intelligence Manufacturing Intelligence Structural Intelligence



Contents

� Introduction

� Micro-Car ec2go




� Outlook



a. Attribute Configurator

Tasks

� Define a safety model for target vehicle

� Define structural performance targets for whole vehicle and car body for

different crash scenarios

− Overall deformation behavior of vehicle

− Trends of force – deformation curves

− Energy of deformation

− Distribution of deformation energy into car body and other parts



- FMVSS208, 0º, 100%, 56 km/h- FMVSS208, 30º, 100%, 56 km/h- ECER94, 0º, 40%, 56 km/h- Euro NCAP, 0º, 40%, 64 km/h- ECER12, 0º, 100%, 53 km/h- Frontal Pole Crash, 30 km/h

Level 0Level 1Level 2

- ECER95, 90º, 50 km/h- Euro NCAP, 90º, 50 km/h- IIHS, 50 km/h- Euro NCAP – Pole, 90º- FMVSS 214 NPRM, 75º- FMVSS 214, static, 90º

Side crash

- ECER34, 0º, 100%, 38 km/h- IIHS, 16 km/h- FMVSS301, 80 km/h- TRIAS 33, 50 km/h

Rear crash

- FMVSS216 – Roof crush- ATZ Bumper Test- ECE-R42 Bumper Test- Pedestrian Safety

General crash tests

Frontal crash

Example: Safety Model for ec2go




…

…

Deformation energy

Energy distribution

Car body Other parts

75 - 80% 20 - 25%

Frontal crash

Example for frontal crash against rigid wall

Know

ledgebase

usin

g C

AE

sim

ula

tions

Application o

f know

ledgebase

for

ec2go

Example: Definition of Targets for ec2go




b. Deformation Configurator

Tasks

� Defining deformation modes for each component of car body

� Defining performance targets for each component

Axial folding

CrumplingMixture of foldingand bending

Bending

Source: ec2go, FH Aachen

…

Modes of deformation observed in “Flexbody” profiles

Basic deformation modes �Simple loads

Axial failure

Bending failure

Reducedto

Reducedto



c. Section Configurator

Tasks

� Develop relatively simple methods for predicting component performance

� Evaluate and choose component design configuration to match pre-

defined performance targets

Parameter 1

Param

eter 2

Semi-empiricalevaluation methods

for predictingcomponent

performance

In a defined design space for component

cross sections

Using tests and CAE simulations

A design approach for lightweight construction of a car body with an example on the micro-car“ec2go”


Contents

� Introduction

� Micro-Car ec2go




� Outlook



Outlook

� Potentials of the FlexBody construction concept are demonstrated through

the Micro-Car ec2go.

� Knowledgebase developed under the ICB approach is applied and

validated using the ec2go car body.

Source: Imperia GmbH



Contact

Thank you for your attention!

Prof. Dr.-Ing. T. RoethImperia GmbHSoerser Weg 9D-52062 AachenTel.: +49 (0)241 608 33 [email protected]

M.Sc. A. Nagle“Automotive Body Engineering”University of Applied Science AachenBoxgraben 98-10052064 AachenTel.: 0241/6009-52934E-Mail: [email protected]



Front crash with rigid wall

Load distribution Acceleration pulse
