Loose weight - win money

Materials Day 2011

Markus Kaufmann

Loose weight - win money

Introduction

The iceberg problem

Poor DesignACQUISITION COST(Research, Design, Test,

Production, Construction)

TRAINING COST

RETIREMENT ANDDISPOSAL COST

TEST AND SUPPORTEQUIPMENT COST

PRODUCT DISTRIBUTION COST

SOFTWARE COST

OPERATION COST

SUPPLY SUPPORT COST

TECHNICAL DATACOST

MAINTENANCE COST

What happened?

Cost benefit of lightweightingis 100 to 1,000 per kg

Figure: DLR Braunschweig

What happened?

Source: Eurocopter

What happens?

In space sector cost benefits of lightweighting are > 10,000/kg

Image: Nasa

• Suggested cost benefit for lightweighting is ca2 /kg

• Procurement is currently dominated by initial costs.

• Cost benefits of lightweightingare ca 10/kg

composiTn: a thematic network on the future use of composites in transport

• Procurement is currently dominated by initial costs.

• Cost benefits of lightweightingare ca 10/kg

Source: U.S. Environmental Protection Agency,

Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through 2006, Appendix D, July 2006.

• Suggested cost benefit for lightweighting is ca2 /kg1,0

1,2

1,4

1,6

1,8

2,0

2,2

2,4

1970 1980 1990 2000 2010

avera

ge w

eig

ht

[tons]

Trucks

Cars

Towards Lightweight Materials

Opportunities and Threats

Opportunities Threats

• higher performance

• lower energy consumption

• lower transport cost

• optimized use of raw material

• legislation

• unknown materials, unknown processes

• higher development cost

• higher material cost

• other issues are

– repair

– design and structural simulations

– crashworthiness

– recycling

– fire safety

Towards Lightweight Materials

Period Material system

70ies: Columbus SL or Reynolds 531

80ies: Titanium bike frame

1982: Unreinforced plastics bike

90ies: Aluminum

90ies: Carbon fibers

1993: Beryllium frame

2010: Flax/carbon frame

Material Evolution for bicycles

Material Evolution for bicycles

Figure: Ashby M. Materials selection in mechanical design

Material Evolution for bicyclesComparison of Materials Used in Bicycles

STEEL TITANIUM

Pros • Inexpensive•Strong•Stiff•Resilient and

•Easy to work with and repair

Cons •Heavy•Corrosive•Designs limited by available tubes and lugs

•Brazing/welding weaker, heat-affected zones

Pros •Light•Strong•Resilient and

•Shock absorbing•Non-corrosive

Cons •Expensive•Designs limited by available tubes

•Not easily repaired•Bad welds are easily hidden

•Stiffness vs. lightweight

ALUMINUM CARBON FIBER

Pros • Inexpensive•Light•Adequately strong•Very stiff for the weight

•Non-corrosive in non-salty environments

Cons •Fatigue risk reqs

overbuilding•Lacks resilience

•Not easily repaired•Bonded joints prone to failure

•Heat treatment can be inconsistent

Pros •Lightest•Strongest•Best shock absorption

•Unlimited design applications

•Non-corrosive•Material has high fatigue resistance

Cons •Expensive•Technology still evolving

•Strength and stiffness are design dependent

•Fully molded styles have very limited sizes

http://www.calfeedesign.com/tech-papers/technical-white-paper/

Steel and metallic alloys

Steel and alloys for bicycle frames

Material specificE-modulus

specific strength

Weight

Carbon steel 25.6 30 140%

Cr-Mo steel 25.6 85 100%

AA-6061-T6 25.9 95 55%

Ti-3Al-2.5V 24.4 156 46%

• carbon steel is corrosive, heavy, strength loss by brazing

• Cr-Mo steel is lighter and more fatigue resistant, weldable

• Aluminum is welded or bonded, very stiff, risks for fatigue

• Titanium is light, strong, but expensive tube sources are aircraft hydraulic lines

http://www.calfeedesign.com/tech-papers/technical-white-paper/

ABM Beryllium Frame

• Beryllium alloy

• aluminum lugs

• adhesive bonded

• 1.1 kg frame weight

•

• 2 ex were built

Source: http://mombat.org/1992AmericanBe1.jpg

Alloys at turbine inlets

Turbine inlet temperature for a selection of Rolls-Royce turbines

thanks to major material developments

1

21

T

TTEfficiency

Source: Aviation and the Environment 03/09

Alloys at turbine inlets

Turbine inlet temperature for a selection of Rolls-Royce turbines

thanks to major material developments

1

21

T

TTEfficiency

Image: Nikon Metrology Blog

Trends in cast alloys (i)

• Hybrid structures

– MnE21 (Magnesium/Manganese/Cerim)

– casted on aluminum or steel sheet

• Thin-walled ductile cast iron

– carbide-free production

– 2-3 mm wall thicknesses

• Aluminium Lithium alloys

– higher specific strength

– better corrosion resistance

Images: Lightweight-Design.de / Alcan Airware

Trends in cast alloys (ii)

• Solution strengthened nodular cast iron

– higher silicon content

– higher yield strength and higher elongations

• Compacted graphite iron

– narrow process window

– combination of strength and thermal conductivity

– engine blocks

• Thixomolding

– high-speed, net-shape injection molding

– semisolid magnesium slurry

– low porosity, complex parts

– reduces risk of burning magnesium

Sources: Thixomat / GoCycle

Plastics

Plastics

Source: lassecollin.se

Plastics

HDT > 150

Ultra Polymers

High-Performance

Polymers

Engineering

Polymers

Commodity

Polymers

100 HDT < 150

HDT < 100

Source: SpecialChem (12/08)

Trends in plastics (i)

• Towards the top of the pyramid

– Self-reinforced plasticse.g. PrimoSpire from Solvay Advanced Polymers

– PEEK and PPSin order to increase the heat deflection temperature (HDT)

(PP PPS PEEK)

• Fillers and reinforcements

– add 30% glass fibers to PA66 (230260

– increase both static properties and HDT

• Hybrid designs

– overmoulding of inserts and metal components

• Increased toughnessSources: SolvayPlastics, SpecialChem (12/08) and Lightweight-Design

Trends in plastics (ii)

Increased Toughness:

Dyneema and Spectra

• UHMwPE fibers with high tensile strength

• better light/UV stability than Aramid/Kevlar

• similar applications as Kevlar, including personal protective equipment, speaker cones,

high-performance ropes and cables

Innegra

• high modulus PP fiber

• low-cost

• similar applications as above

Source: Xtreme Degreez Sports Magazine

Example: Innegra reinforced concrete

Source: Wikinnegra.com

Trends in plastics: Self-reinforced

• Curv is self-reinforced polypropylene

PP Curv

Density kg/m3 900 920

Notched Izod impact kJ/m2 4 400

Tensile strength MPa 27 120

Tensile modulus GPa 1.12 4.2

Sources: Materials World, Vol. 6 No. 10 pp. 608-09 ,1998 / Samsonite / curvonline / matweb

Composites

Example: Composite Bike Frame

Images: www.lotustalk.com

Case study: Optimization of C-Spar

• milled aluminum AA7010-T73651

• resin transfer molded carbon/epoxy

– RTM6

– non-crimp fabric

• autoclave carbon/epoxy prepreg

– M21/T800

– Plain Weave

Kaufmann, Zenkert, Åkermo. Journal of Aircraft (0021-8669) 2011 vol. 48 no. 3

Case study: Optimization of C-Spar

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[kg]

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[€]

Alu

RTM

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RTM

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RTM

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RTM

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Kaufmann, Zenkert, Åkermo. Journal of Aircraft (0021-8669) 2011 vol. 48 no. 3

Trends in Composites (i)

• shorter cycle time

– through automation

– fast curing thermosets

– thermoplastics

enables cost reductionfor automotive and aerospace

• cost-effective processes

– hybrid processes

– out-of-autoclave

• new material systems

– tougher

– cheaper

– greener

Images: Coriolis Composites, BMW

Trends in Composites (ii)

Images: Roltex, FiberShell, GreenCore, Museeuwbikes, Innobat, Huntsman Advanced Materials

Message

Design with

OpportunitiesACQUISITION COST

(Research, Design, Test,

Production, Construction)

TRAINING COST

RETIREMENT AND

DISPOSAL COST

TEST AND SUPPORT

EQUIPMENT COST

PRODUCT DISTRIBUTION COST

SOFTWARE COST

OPERATION COST

SUPPLY SUPPORT COST

TECHNICAL DATA

COST

MAINTENANCE COST

Questions?