Lightweight Design - Comprehensive evaluation based ... · Impact assessment Evaluation Consideration of environmental regulations and the legislative framework for sustainable production

© ika 2017 · All rights reserved2017/11/28Slide No. 1175600 · 17abu0051.pptx

Shanghai, November 28th, 2017

Alexander Busse, M.Sc.

Lightweight Design -

Comprehensive evaluation based decision model for optimized components

International Automotive Congress 2017

Institute for Automotive Engineering


Agenda

Motivation for Lightweight Design

OEM and Supplier Perspective for Lightweight Innovations

Comprehensive Decision Model for Lightweight Components

Exemplary Application of Decision Model

Summary


Requirements of future vehicle concepts: Efficiency, Safety and Driving

Experience

Vehicle requirements are influenced by main drivers, e.g. CO2 legislation, Vision

Zero, customer needs

Conflict of goals for the vehicle requirements demand of innovative technologies

Statement of the EC concerning the integrated product policy also includes the

phases prior to and after the use of the vehicle new challenges to ensure

vehicles that are complying with legislation

New technologies to meet overall vehicle requirements

Motivation for Lightweight DesignReversing the weight spiral

Efficiency

Safety

CO2 regulation

Vision Zero

Customer

New technologies

Vehicle requirements

Automotive industry

Solutions

Product-

lifecycle

Driving

experience

OEM

Suppliers

Ima

ge

so

urc

es: O

pe

l, ika

Increasing demands and customer needs result in an increased mass

especially in vehicle body and E/E

Secondary effects which lead to an increase in weight in chassis and

powertrain

Safety [+kg]

Comfort [+kg]

Performance [+kg]

Space [+kg]

Variability [+kg]

Quality [+kg]

W e i g h t s p i r a l

Pro

ble

m-s

olv

ing

ap

pro

ac

h

Increasing demands led to higher vehicle weight


Motivation for Lightweight Design Improvement of performance and efficiency are the main drivers

Mass reduction decreases

necessary power for the same

driving dynamics as well as stress

on certain components

Reduction of vehicle mass enables

potential of scaling other

components, e.g. engine, brakes,

suspension, at the same driving

performance.

Secondary lightweight potential

is up to 50 %

Longitudinal dynamics:

Better acceleration

Shorter braking distance

Vertical and lateral dynamics:

More agile handling

Generally:

Improved safety

Less load / stress on vehicle

Smaller battery system size

A significant improvement of

efficiency is necessary to satisfy

global CO2 legislation

100 kg of weight reduction lead to

an improvement of fuel

consumption by 0.1 to 0.3 l/100km

in norm cycles

This corresponds to a decrease of

CO2 emissions by 3 to 7gCO2/km

Due to the less amount of material,

needed for production, there is a

potential to reduce vehicle price

Additionally, better fuel economy

has a direct impact on operational

cost

Less expensive battery systems can

be used to achieve the same range

for xEV

Improvement of

driving dynamics

Reduction of CO2 emissions

and fuel consumption

Cost

reduction

Secondary lightweight

potential

Main drivers Extended potential

Ima

ge

so

urc

es: O

pe

l, fo

tolia

.co

m / G

ina

Sa

nd

ers

, S

iem

en

s V

DO


Agenda





Summary


OEM and Supplier Perspective for Lightweight InnovationsProduct stewardship against the ecological influence demandsholistic evaluation of lightweight design

OEM

Tier 1/2

Tier 3+

Material supplier

Ecological

influence

∑ = 7.6 t CO2eq/vehicle

Product

stewardship

Reference vehicle

Mercedes-Benz

C 250, MY 2015

6%12%14%

23%

45%

E/EInteriorChassisDrivetrainBody

GHG emissions (production) in passenger vehicle production by vehicle domain

The need for a holistic evaluation of lightweight design

Increasing ecological requirements for future vehicles along the complete life cycle

The emphasis of the ecological influence and product stewardship are partly located at the opposite ends of the value chain

Holistic potential analysis including LCA of a lightweight innovations is important in early phase of the vehicle development Ima

ge

so

urc

es: M

erc

ed

es-B

en

z

Body domain with highest share of GHG

OEM performs a significant value

contribution and has considerable

ecological influence

Material suppliers have the largest

influence on the LCA of the corresponding

components

Drivetrain and Chassis:

Comparable long value added chain

Ecological influence of the OEM is limited

Supplier carry production stewardship


Agenda





Summary


Secondary potential is assessed in multiple iterations

Comprehensive Decision Model for Lightweight ComponentsPrimary lightweight design potential: efficiency, dynamics, safetyReversing the weight spiral with secondary lightweight design

Efficiency benefits

Evaluation of driving dynamics and driving safety

SimulationsmodellEingangsdaten Ergebnisse

0 100 200 300 400 500 600 700 800 900 10000

40

80

120

v [km

/h]

0 100 200 300 400 500 600 700 800 900 1000-200

-100

0

100

T [N

m]

0 100 200 300 400 500 600 700 800 900 10000

2000

4000

6000

n [rp

m]

0 100 200 300 400 500 600 700 800 900 100058

60

62

64

66

68

70

SO

C [%

]

t [s]

ICEEM

ICEEM

ZuFi

2LwRZdem

xmme

v2

AcfpFF

a

Fahr- und Lastprofile

Input data Simulation model Results

Driving and load

profiles

Driver

ICE

Auxiliaries

ClutchTransmission

Differential

VehicleDriving resistance

Energy saving potentials of 100 kg mass reduction

Comprehensive drivetrain simulation model to

quantify fuel consumption and CO2 emissions

Deceleration from 100 km/h

Longitudinal dynamics

Steady-state circular driving

Lateral dynamics, quasi-stationary

Double lane change

Lateral dynamics, dynamic

Bad road conditions

Comfort

1 2

3 4

Velo

city Start of braking

Standstillx

Vert

ical

dis

pla

cem

ent

Route profile

Time [s]

Manoeuvres

Multibody simulation model with parameterization of global vehicle

values

Manoeuvres

Ima

ge

so

urc

es: h

ttp

://a

uto

mo

tive

-te

ch

no

log

y.d

e, G

M

0.12 - 0.15 l/100km

0.35 - 0.4 kWh /100km

Midsize Vehicle, NEDC driving cycle

ICE

xEV

++

++

+

o

Engine map

Curb weight / total weight Transmission ratio of dual-clutch

gearbox

Transmission ratio gear box/ drive shaft

Rolling resistance coefficient Dynamic wheel radius

Drag resistance coefficient

Reference area Density of ambient air

Input Data:

Primary Mass Reduction

Straight driving at flat, dry

asphalt road No loss of efficiency

Constant rolling resistance

coefficient

Assumptions:

Torq

ue

RPM

Reference

Reduced

mass

Determination of new engine map due

to reduced mass (keeping the acceleration potential)

Energy absorption

Torque transmission

Total vehicle

weight

Driving range Engine weight

Int. Step 2 - Selected Components:

Intermediate Step 1 - Engine Map:


Pro

ble

m-s

olv

ing

ap

pro

ac

h

Empirical approach based on benchmark data of real passenger

vehicles

Analytical approach based on component design equations

Simulative approach based on explicit Finite Element crash

simulations

Determination of Secondary Mass Reduction:

Enables additional 30-50 % of the primary mass reduction


Comprehensive Decision Model for Lightweight ComponentsEnergetically and ecological assessment using LCA

Structure of life cycle analysis

Environmental Analysis

LCA Target and scope

Life Cycle Inventory

Life Cycle Assessment

Impact assessment

Evaluation

Consideration of environmental regulations and the legislative framework for sustainable production

Portfolio of manufacturing techniques for the production of components

Selection of the relevant life-cycle phases and analysis dimensions for the following detailed analysis

(according to ISO 14040)

Detailed technical information on relevant component

Analysis of the reference process and the innovative process with regard to defined

analysis dimensions

Validation of the calculation results by parameter variation

Interpretation of results and action recommendationsLCA

(Raw) material

production

1 Production2 Use3 Recycling and

recovery

4

cradle to gatecradle to grave

Life cycle phases


Comprehensive Decision Model for Lightweight ComponentsMethodology for lightweight innovation analysis

LCA

Reference emissions

Relative emission

intensityPrioritization of

components in the

vehicle

Absolute emission potential

Relative emission potential

Relative weight

potential

Holistic technological and ecological potential of lightweight

innovation

Safety & driving

dynamics

Efficiency


Pro

ble

m-s

olv

ing

ap

pro

ac

h


design

Lightweight innovation

I

IV

I

II

III

Methodological steps of holistic analysis

V

I

IV

II

III

V

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Relative mass potential

Rela

tive e

mis

sio

n in

tensity

Evaluation of primary lightweight design potential

Assessment of secondary lightweight design potential

Comprehensive life cycle assessment

Quantitative evaluation of emission potential

Assessment of the considered strategic alternatives

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Re

lative

em

issio

n in

tensity


Lightweight technology

not favorable


favorable


Agenda





Summary


0.07

0.15

0.22

0.35

0.08

0.15

0.23

0.35

0.06

0.12

0.18

0.28

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

Const. velocity NEFZ NEFZ_mod NEFZ_AA

Fu

el co

nsu

mp

tio

nre

du

ctio

n[l/1

00

km

/10

0kg]

Otto-NA

Otto TC

Diesel TC

Exemplary Application of Decision Model Primary lightweight design potential

Efficiency benefits Evaluation of driving dynamics and driving safety

Manoeuvres

A cumulated lightweight potential of 42 kg in the drivetrain and chassis of a medium-sized reference vehicle is exemplary used for application

++

++

+

o

Deceleration from 100 km/h

Longitudinal dynamics

Steady-state circular driving

Lateral dynamics, quasi-stationary

Double lane change

Lateral dynamics, dynamic

Bad road conditions

Comfort

40.0

39.0

38.0

37.0

36.0

35.0

2.62.52.42.32.22.12.0

Bra

kin

gdis

tance

[m]

Time [s]

Lightweight model

Reference model Reference vehicle with a TC ICE benefits of the exemplary

assessed cumulated 42 kg mass reduction with an improved fuel

economy by 0.52 %

Extrapolation of this result: around 0.1 l/100km/ 100 kg

The efficiency benefit can be increased in cycles with higher

dynamics (NEFZ_mod) and by adjusting engine and

transmission setup to lower vehicle mass (NEFZ_AA)

∆ = 0.5 m


Exemplary Application of Decision Model Secondary lightweight design potential

1730

1740

1750

1760

1770

1780

1790

1800

1810Loop 1

Drivetrain 3.49 kg

Chassis 8.28 kg

Body 3.28 kg

Total 15.06 kg

Loop 2

Drivetrain 1.20 kg

Chassis 1.38 kg

Body 2.67 kg

Total 5.25 kg

Loop 3

Drivetrain 0.38

Chassis 0.51 kg

Body /

Total 0.89 kg

Reference

Primary

Secondary - Loop 2

Secondary - Loop 3

Ve

hic

le m

ass [kg

]

Secondary - Loop 1

Secondary potential is assessment in multiple iterations W e i g h t s p i r a l

Pro

ble

m-s

olv

ing

ap

pro

ac

h

Findings

Exemplary 42 kg mass reduction are

evaluated in empirical- analytical-,

and simulative approaches

Primary mass reduction of 42 kg

leads to a total secondary mass

reduction of 15.06 kg + 5.25 kg +

0.89 kg = 21.2 kg.

This represents 50 % of the primary

mass reduction


Exemplary Application of Decision Model Life cycle analysis

Drivetrain Chassis

A cardan drive shaft of a passenger car

serves as a reference component

Lightweight variants: high-strength steel,

aluminum and CFRP

−24%−25%

4

9.8 kg

Process

potential

flow

forming

Process

potential

forging

−8%

3 Material

potential

CFRP

−31%

−57%

5.6 kg

6Process

potential

hot

rolling

−18%

1

13.0 kg10.7 kg+1%

Material

potential

aluminum

2

10.6 kg

5

7.4 kg

1 Steel ref. (incl.

wheel covers)

2 Steel optimized

3 Cast aluminum

4 Aluminum flow

forming

5 Forged aluminum

6 CFRP

Steel Aluminum CFRP

3.9 kg

Material

potential

CFRP

−25%

Aluminum

5.2 kg

Material

potential

aluminum

− 15%

Steel

optimized

6.1 kg

Material

potential

HSS

CFRP

−56%

− 31%

Steel

reference

8.8 kg

Ima

ge

so

urc

es: ve

locity-g

rou

p.d

e, O

tto

Fu

ch

s

Reference wheel of a midsize vehicle

High-strength steel, aluminum and CFRP

are evaluated against a conventional steel

wheel

Two example components from drivetrain and chassis are assessed in terms of primary energy requirement and global warming potential

(GWP100) of different lightweight design variants


Exemplary Application of Decision Model Results of life cycle analysis

Drivetrain Chassis

HSS allows reduction in emissions by 22 %

Aluminum variant achieves a GWP-reduction of 56 %

An optimistic CFRP case shows GHG emissions - 39%

Ima

ge

so

urc

es: ve

locity-g

rou

p.d

e, O

tto

Fu

ch

s

The forged aluminum wheel shows the lowest GHG emissions,

35 % below the results of the steel reference wheel

Retrenchment of raw material can overcompensate the higher

GHG intensity

Baseline scenario

Vehicle with a gasoline engine and a total mileage of 150,000 km

Impact analysis for e.g. energy mix, transport route, recycling quota

Further scenarios vary the parameters drivetrain topology and vehicle mileage, diesel, plug-in hybrid and battery-electric drivetrains and

mileages of 150,000 and 250,000 kilometers

0

50

100

150

200

250

300

350

GW

P1

00

[kg

CO

2e

q]

SteelReference

12,4 kg

optimized

10,6 kg

Aluminumcast10,7 kg

CFRPoptim.5,6 kg 5,6 kg

Basis5,6 kg

conserv.forged7,4 kg

Raw Material Production Use EoL Sum Steel Reference

0

50

100

150

200

250

GW

P1

00

[kg

CO

2e

q]

SteelReference

Steeloptimized

Aluminum CFRPoptimistic Basic Conserv.

8,8 kg 6,1 kg 5,2 kg 3,9 kg 3,9 kg 3,9 kg

Raw material Production Use EoL Sum Steel Reference


0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Re

lative

em

issio

n in

ten

sity


Exemplary Application of Decision ModelConsolidation allows comparability of individual components

LCA can be used as strategic decision tool


not favorable


favorable

Relative emission potential over the whole life cycle as decision basis

Environmental performance of component strongly depends on

material production processes, manufacturing and realized mass

reduction

Relative emission intensity

Increase or reduce GHG emissions due

to material substitution and / or process

adjustment

Absolute emission potential Ei

Relative emission potential ei


Reduction of GHG emissions

due to mass reduction

LCA

Standardization of LCA results

𝐸𝑖 = 𝐺𝑊𝑃𝑟𝑒𝑓 − 𝐺𝑊𝑃𝑖= 𝑚𝑟𝑒𝑓 ∙ 𝑖𝑟𝑒𝑓 −𝑚𝑖 ∙ 𝑖𝑖

𝑀𝑖 =𝑚𝑟𝑒𝑓 −𝑚𝑖

𝑚𝑟𝑒𝑓= 1 −

𝑚𝑖

𝑚𝑟𝑒𝑓Ii =

iiiref

=𝐺𝑊𝑃𝑟𝑒𝑓 ∙ 𝑚𝑟𝑒𝑓

𝑚𝑖 ∙ 𝐺𝑊𝑃𝑟𝑒𝑓

𝑬𝒊 = 𝒎𝒓𝒆𝒇 ∙ 𝒊𝒓𝒆𝒇 ∙ 𝒆𝒊 𝒘𝒊𝒕𝒉 𝒆𝒊 = 𝟏 − (𝟏 −𝑴𝒊) ∙ 𝑰𝒊


Agenda





Summary


SummaryHolistic Analysis Method for Lightweight Design

Lightweight design is an important instrument to comply with the requirements of future vehicle

generations: efficiency, safety and driving experience

The innovation process for lightweight technologies is shaped by both, OEM with the responsibility for

the complete vehicle and suppliers with different vertical integration levels in the value chain

A holistic evaluation for innovations as part of an efficient technology strategy is of high importance

Primary lightweight potential in terms of fuel consumption reduction and increase of vehicle safety

and driving comfort. Secondary lightweight effects allow up to 50% further mass reduction.

Increasing relevance of ecological sustainability, require holistic, life cycle based approach for

lightweight design evaluation

Transparent, LCA based model as key success factor to reduce innovation barriers along the supply

chain

Life Cycle Assessment as basis to derive absolute and relative emission potential of lightweight

components

The integration of primary and secondary potential enables quantitative analysis

The proposed methodology facilitates the holistic evaluation of lightweight innovations and the

scenario-based assessment of different lightweight options

Motivation for lightweight design and the need for a holistic evaluation model

Holistic model for lightweight innovation analysis

Assessment of the considered lightweight alternatives

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Rela

tive e

mis

sio

n inte

nsity


Standardization of LCA results LCA can be used as strategic decision tool

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Rela

tive e

mis

sio

n inte

nsity


Component

Wheel

Drive shaft

Material

CFRPAluminium

Steel

Emission increase

Emission decrease

Aluminum forged

Steel Reference

e = 0,2

e = 0

e = 0,6

e = 0,4

e = 0,8


not favorable


favorable

Relative emission potential over the whole life cycle as

decision basis

Environmental performance of component strongly depends on

material production processes, manufacturing and realized

mass reduction

LCA

Reference emissions

Relative emission

intensityPrioritization of

components in the

vehicle

Absolute emission potential

Relative emission potential

Relative weight

potential

Holistic technological and ecological potential of lightweight

innovation

Safety & driving

dynamics

Efficiency


Pro

ble

m-s

olv

ing

ap

pro

ac

h


design

Lightweight innovation

I

IV

I

II

III

Methodological steps of holistic analysis

V

I

IV

II

III

V

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7


Rela

tive e

mis

sio

n in

tensity

Evaluation of primary lightweight design potential

Assessment of secondary lightweight design potential

Comprehensive life cycle assessment

Quantitative evaluation of emission potential

Assessment of the considered strategic alternatives

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Rela

tive e

mis

sio

n inte

nsity



not favorable


favorable

DescriptionLightweight design viewpoints of OEM and supplier differ

Component

layer

Vehicle layer

Fleet layer

OE

M p

ers

pecti

ve

Su

pp

lier

pers

pecti

ve

Legislative

requirements

Customer

requirements

OEM

requirements

Technology management and the assessment of lightweight innovations is characterized by the different viewpoints of OEM and OES

OEM perspective for lightweight component development is driven top-down by the optimization

OES have a high level of component expertise and implements innovations in a bottom-up approach

Fleet

Vehicle

Component

Top-down optimization of the

vehicle fleet to meet

legislative requirements

Complete vehicle is focused

in order to meet customer

and market demands

Bottom-up development of

components by suppliers

order to meet OEM demands

and vehicle requirements


Phone

Fax

Email

Internet www.ika.rwth-aachen.de

Institute for Automotive Engineering (ika)

RWTH Aachen University

Steinbachstr. 7

52074 Aachen

Germany

Contact

Alexander Busse, M.Sc.

Senior Expert Lightweight Design

+49 241 80 25586

+49 241 80 22147

[email protected]

Documents

Lightweight Design - Comprehensive evaluation based ... · Impact assessment Evaluation Consideration of environmental regulations and the legislative framework for sustainable production