Incorporating Green Engineering in Material Selection and Design S.L. Kampe Associate Professor...

Incorporating Green Engineering in Material Selection and Design

S.L. Kampe

Associate ProfessorMaterials Science and Engineering Department

Virginia Tech

18th Annual National Educators’ Workshop19-22 October 2003Newport News and Hampton, Virginia

Materials Science and Engineering2003 National Educators’ Workshop

Material Selection and Design - Background

∆ MSE 4055 - Material Selection and Design• MSE required, senior level• Technical elective for ISE, ESM, ME, AOE, Arch, + others.• Material Selection as it influences the outcomes of engineering design

– in a general sense– green issues

∆ Methodology- Identification of appropriate material selection indices

i. Define design objectiveii. Determine constitutive relationshipiii. Separate design needs (extensive) from material response groups (intensive)

- 2-D material selection charts in the manner of AshbyM.F. Ashby, Materials Selection in Mechanical Design, 2nd Ed., B-H, Oxford, 1999.

- Cambridge Engineering Selector application softwareCES4.1, Granta Design, Ltd., 2003

∆ Disclaimers- Illustrative of an approach- Several layers of analysis required- Not a final solution to the complex problem


Examples

• Selecting a material to solve a specific environmental problem

» Identify a suitable alternative to asbestos as an insulating material

• Enabling the routine assessment of green issues in generic engineering design » Lifetime Energy Consumption attributable to a component placed in

a transportation system


TLC = Initial Cost + Lifetime Operational Costs

An alternative to asbestos insulation

Objective: Identify an insulating material to replace asbestos to reduce total lifetime cost (TLC).

r

CE = Exchange Constant = $-value of Energy ( $ / J)

TLC ( $ / m2 ) ≈ · CM· r + k

Tr

tCE123

123

Material Contribution

123

design requirements

123123 123

(e.g., due to heat losses)(purchase price of the material) Design Needs

r = thickness (m)

T = temperature difference (K)

Material Response Constants

= material density (kg/m3)

CM = per-mass cost ($/kg)

k = thermal conductivity (J/kg·K·s)

CE = exchange constant ($ / J)


Exchange Constant: the $-value of energy

Energy Source

CoalOil

Natural GasGasoline (US)

Gasoline (Europe)Electricity (resistance)

Cost ( US$ / MJ )

0.003 - 0 0040.007 - 0.0120.005 - 0.0080.012-0.0150.03-0.040.02 - 0.06

from M.F. Ashby, Materials Selection: Multiple Constraints and Compound Objectives, CUED/C-EDC/TR38, Cambridge Engineering Design Center, Cambridge University Engineering, April 1996, p.1.13

Exchange Constant



Cambridge Engineering Selector (CES) Ver. 4.1



Increasing Initial Cost

Incr

easi

ng C

ost

of

Opera

tion

Cambridge Engineering Selector (CES 3.1)




Incr

easi

ng S

erv

ice C

ost

Selected Candidate Materials

Property-range midpoint valuesFrom CES3.1, 2000

0.01

0.1

1

101 102 103

Th

erm

al C

on

du

ctiv

ity,

W/m

·K

( R

ela

tes

to C

ost

of

En

erg

y L

ost

Du

rin

g S

erv

ice

)

Density · Price, US$/m3

( Relates to Initial Cost )

Hokie Stone (Limestone)

Cement

Cork

Cordierite Foam

Cellulose Insulation

Mullite Foam

PE FoamGlass Wool

Melamine Foam

PU Elastomeric Foam

Vermiculite

LD Flexible Polymer

PU Foam

Plaster of Paris

Glass Foam

Asbestos



Coal as an Energy Source

An alternative to Asbestos Insulation

Assumed Design Needs

T ≈ 40 K

r ≈ 7 cm

t = 0.5 (blue) or 5 year (red)

Assumed Material Response

kasbestos ≈ 0.4 W/m·K

( * CM)asbestos ≈ 494 $/m3


Incr

easi

ng S

erv

ice C

ost

0.01

0.1

1

101 102 103

Th

erm

al C

on

du

ctiv

ity,

W/m

·K

( R

ela

tes

to C

ost

of

En

erg

y L

ost

Du

rin

g S

erv

ice

)

Density · Price, US$/m3

( Relates to Initial Cost )

Hokie Stone (Limestone)

Cement

Cork

Cordierite Foam

Cellulose Insulation

Mullite Foam

PE FoamGlass Wool

Melamine Foam

PU Elastomeric Foam

Vermiculite

LD Flexible Polymer

PU Foam

Plaster of Paris

Glass Foam

0.5-year Lifetime

5-year Lifetime

Asbestos

Lines of Comparable Lifetime Cost (relative to Asbestos)

Contours of Decreasing Lifetime Cost


Lifetime Energy Consumption - Transportation Systems

Ex. A component on a transportation system loaded in bending- L fixed by design- P predicted by design

Constitutive Equations:

McI

3PL2

4bh2 mAL

m 3

4 2P L7 / 2

2 / 3

f

2/ 3

Minimum mass (e.g., kg) required to

fulfill requirements of strength-limited design (fixed beam aspect ratio)

Q 3

4 2P L7 / 2

2 / 3

q

f2 / 3

Energy (e.g., MJ) required to fulfill requirements of strength-limited design, for q in MJ/kg

P = distributed load (e.g., N/m)L = length (e.g., m)b,h = cross sectional dimensions (e.g., m)

= failure stress (e.g., MPa)

= density (e.g., kg/m3)

q = Energy content (e.g., MJ/kg)


LEC 3

4 2P L7 / 2

2 / 3

q

f2 / 3

3

4 2P L7 / 2

2 / 3

f2 / 3

CE

Lifetime Energy Consumption (LEC) = Initial Energy Expenditure+ Energy Expended during Service

Exchange constant relating mass to energy expenditure

LEC/

q

f2 / 3

f2 / 3

CE P = distributed load (e.g., N/m)

L = length (e.g., m)b,h = cross sectional dimensions (e.g., m)

f = failure stress (e.g., MPa)

= density (e.g., kg/m3)

q = Energy content (e.g., MJ/kg)


Objective: Minimize Lifetime Energy Consumption


Estimating an Exchange Constant

Hypothetical Example:

• 3,000 kg vehicle: 14 mpg • Energy value of Gasoline ≈ 126 MJ/gal1,800 kg vehicle: 19 mpg • 50,000 mile lifetime

50,000mileslifetime

xgal. fuel14miles

x126MJ

gal. 450,000

MJ consumedlifetime

50,000mileslifetime

xgal. fuel19miles

x126MJ

gal. 331,580

MJ consumedlifetime

CE

MJm

(450,000 331,580) MJ

(3,000 1,800) kg99

MJkg

For the 3,000 kg vehicle and a 50,000 mile lifetime:

For the 1,800 kg vehicle and a 50,000 mile lifetime:



10

100

104 105

Ma

ss In

de

x

/

2/3

( kg

/ m

5/3

·MN

2/3 )

Strength-limited Energy Index

·q / 2/3 ( MJ / m

5/3·MN

2/3 )

Epoxy-Kevlar Composite

1015 Steel403 SS

6061-T6

Mg AZ61 Alpha Ti Gr 6

Ti MMCCFRP

GFRP

Be S-200

Al Foam

Alumina CMC

Increasing Initial Energy Expenditure

Incr

easi

ng L

ifeti

me E

xpendit

ure Selected Candidate Materials

Property-range midpoint valuesFrom CES3.1, 2000



10

100

104 105

Ma

ss In

de

x

/

2/3

( kg

/ m

5/3

·MN

2/3 )


·q / 2/3 ( MJ / m

5/3·MN

2/3 )


1015 Steel403 SS

6061-T6


Ti MMCCFRP

GFRP

Be S-200

Al Foam

Alumina CMC

CE = 99 MJ/kg

( 50,000 mi. lifetime )

CE = 395 MJ/kg



Incr

easi

ng L

ifeti

me E

xpendit

ure




Incr

easi

ng L

ifeti

me E

xpendit

ure

10

100

104 105

Ma

ss In

de

x

/

2/3

( kg

/ m

5/3

·MN

2/3 )


·q / 2/3 ( MJ / m

5/3·MN

2/3 )


1015 Steel403 SS

6061-T6


Ti MMCCFRP

GFRP

Be S-200

Al Foam

Alumina CMC

CE = 395 MJ/kg

( LEC' = 0.5·LEC'o )

CE = 395 MJ/kg




Summary

• Material selection is a decision-requiring event in design

• Green-based material selection indices and charts provide a means to routinely assess environmental issues relevant to the decision-making process

• One of several criteria necessary to consider in design

Note: Contents of this talk can be found in the following published manuscripts:

• S.L. Kampe, “Method to Incorporate Green Engineering in Material Selection and Design,” Proceedings of the American Society for Engineering Education Annual Conference and Exposition, (Proc. Int. Conf., Montreal, 17-19 June 2002), ASEE, Washington, D.C., 2002, pp. 1625.1-1625.7. http://www.asee.org/conferences/proceedings/search.cfm

• S.L. Kampe, “Incorporating Green Engineering in Materials Selection and Design,” 2001 Green Engineering Symposium Proceedings (Proc. Conf., Roanoke, Virginia, August 2001), Blacksburg, 2001, pp. 7-1 – 7-6. Also featured at http://www. grantadesign.com/userarea/papers/cust1.htm.

Incorporating Green Engineering in Material Selection and Design


Acknowledgements

• Virginia Tech College of Engineering

- Green Engineering Program

• Virginia Tech Materials Science and Engineering Department

• Granta Design, Ltd.

Incorporating Green Engineering in Material Selection and Design S.L. Kampe Associate Professor...

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