Incorporating Green Engineering in Material Selection and Design S.L. Kampe Associate Professor Materials Science and Engineering Department Virginia Tech 18th Annual National Educators’ Workshop October 2003 Newport News and Hampton, Virginia

Materials Science and Engineering 2003 National Educators’ Workshop Material Selection and Design - Background ∆ MSE 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 objective ii.Determine constitutive relationship iii.Separate design needs (extensive) from material response groups (intensive) -2-D material selection charts in the manner of Ashby M.F. Ashby, Materials Selection in Mechanical Design, 2 nd Ed., B-H, Oxford, Cambridge Engineering Selector application software CES4.1, Granta Design, Ltd., 2003 ∆ Disclaimers -Illustrative of an approach -Several layers of analysis required -Not a final solution to the complex problem

Materials Science and Engineering 2003 National Educators’ Workshop 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

Materials Science and Engineering 2003 National Educators’ Workshop 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 C E = Exchange Constant = $-value of Energy ( $ / J) TLC ( $ / m 2 ) ≈  · C M ·  r +  Material Contribution  design requirements  (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/m 3 ) C M = per-mass cost ($/kg) k = thermal conductivity (J/kg·K·s) C E = exchange constant ($ / J)

Materials Science and Engineering 2003 National Educators’ Workshop Exchange Constant: the $-value of energy Energy Source Coal Oil Natural Gas Gasoline (US) Gasoline (Europe) Electricity (resistance) Cost ( US$ / MJ ) 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 An alternative to asbestos insulation

Materials Science and Engineering 2003 National Educators’ Workshop Cambridge Engineering Selector (CES) Ver. 4.1 An alternative to asbestos insulation

Materials Science and Engineering 2003 National Educators’ Workshop Increasing Initial Cost Increasing Cost of Operation Cambridge Engineering Selector (CES 3.1) An alternative to asbestos insulation

Materials Science and Engineering 2003 National Educators’ Workshop Increasing Initial Cost Increasing Cost of Operation Cambridge Engineering Selector (CES 3.1) An alternative to asbestos insulation

Materials Science and Engineering 2003 National Educators’ Workshop Increasing Initial Cost Increasing Service Cost Selected Candidate Materials Property-range midpoint values From CES3.1, 2000 An alternative to asbestos insulation

Materials Science and Engineering 2003 National Educators’ Workshop 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 k asbestos ≈ 0.4 W/m·K (  * C M ) asbestos ≈ 494 $/m 3 Increasing Initial Cost Increasing Service Cost Lines of Comparable Lifetime Cost (relative to Asbestos) Contours of Decreasing Lifetime Cost

Materials Science and Engineering 2003 National Educators’ Workshop 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: Minimum mass (e.g., kg) required to fulfill requirements of strength-limited design (fixed beam aspect ratio) 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/m 3 ) q = Energy content (e.g., MJ/kg)

Materials Science and Engineering 2003 National Educators’ Workshop Lifetime Energy Consumption (LEC) = Initial Energy Expenditure + Energy Expended during Service Exchange constant relating mass to energy expenditure 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/m 3 ) q = Energy content (e.g., MJ/kg) Lifetime Energy Consumption - Transportation Systems Objective:Minimize Lifetime Energy Consumption

Materials Science and Engineering 2003 National Educators’ Workshop Estimating an Exchange Constant Hypothetical Example: 3,000 kg vehicle: 14 mpg Energy value of Gasoline ≈ 126 MJ/gal 1,800 kg vehicle: 19 mpg 50,000 mile lifetime For the 3,000 kg vehicle and a 50,000 mile lifetime: For the 1,800 kg vehicle and a 50,000 mile lifetime: Lifetime Energy Consumption - Transportation Systems

Materials Science and Engineering 2003 National Educators’ Workshop Increasing Initial Energy Expenditure Increasing Lifetime Expenditure Selected Candidate Materials Property-range midpoint values From CES3.1, 2000 Lifetime Energy Consumption - Transportation Systems

Materials Science and Engineering 2003 National Educators’ Workshop Increasing Initial Energy Expenditure Increasing Lifetime Expenditure Lifetime Energy Consumption - Transportation Systems

Materials Science and Engineering 2003 National Educators’ Workshop Increasing Initial Energy Expenditure Increasing Lifetime Expenditure Lifetime Energy Consumption - Transportation Systems

Materials Science and Engineering 2003 National Educators’ Workshop 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, June 2002), ASEE, Washington, D.C., 2002, pp 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 grantadesign.com/userarea/papers/cust1.htm. Incorporating Green Engineering in Material Selection and Design

Materials Science and Engineering 2003 National Educators’ Workshop Acknowledgements Virginia Tech College of Engineering -Green Engineering Program Virginia Tech Materials Science and Engineering Department Granta Design, Ltd.