PSI - Issue 8

G. Fargione et al. / Procedia Structural Integrity 8 (2018) 566–572 Author name / Structural Integrity Procedia 00 (2017) 000–000

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As a consequence, the problem of optimal materials choice and components dimensioning for tubes can be formulate as follows: define the geometric parameter t and the material of tubes M, that optimize (or balance) the performance function PF (5) and the efficiency function EF = │ CR – 1 │ , while respecting the constraints on requirement (6), the fixed value of geometric parameters d o and L t , and the constraint on thermal linear expansion between tubes and shell. In the case of this simple application, just two kind of investigation have been carried out with varying the weight coefficients of the two objective function PF and EF: 1) both coefficient equal to 0.5; 2) EF coefficient null, so excluding the principle of efficiency from the choice of material and the sizing of the component. As a result, while the optimal solutions for material choice have been substantially unchanged (in both cases Fe Cr-Ni alloy A-286 as first choice), the tube thickness has been smaller in the first case (1.245 mm against 1.473 mm, according TEMA standardized tube thickness for outer diameter of 19.05 mm), confirming the influence of the efficiency criterion in guiding the search for the optimal material-thickness solution. The proposed method for materials selection in multi-component systems design, has been conceived to solve the problem of matching best choice of materials with components dimensioning, applying an efficiency principle, to obtain solutions calibrated on real performance needs, and to avoid waste of excessive performing materials and overdimensioning. Some interesting results have been obtained: a systemic approach to the problem of optimal choice of materials in multi-component environment has been generalized; the problem of optimal selection of the material has been extended to the dimensioning of the components; a principle of efficiency in the choice of material and sizing has been formalized in the problem. The application in plant component design showed how the method can be applied in the engineering design practice, and confirmed the influence of the efficiency criterion in guiding the search for the optimal solution. Ashby, M.F., Brechet, T.J.M., Cebon, D., Salvo, L., 2004. Selection Strategies for materials and Processes. Materials and Design 25, 51–67. Athawale, V.M., Chakraborty, S., 2012. Material Selection Using Multi-Criteria Decision-Making Methods: A Comparative Study. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 226, 266–285. Chatterjee, P., Athawale, V.M., Chakraborty, S. 2009. Selection of Materials Using Compromise Ranking and Outranking Methods. Materials and Design 30, 4043–4053. Chiner, M., 1988. Planning of Expert Systems for Materials Selection. Materials and Design 9, 195–203. Dieter, G.E., 2000. Engineering Design: A Materials and Processing Approach . McGraw-Hill. Farag, M.M, 1989. Selection of Materials and Manufacturing Processes for Engineering Design . Prentice Hall. Farag, M.M., 2002. Quantitative Methods of Materials Selection . In: Kutz, M. (Ed.). Handbook of Materials Selection . John Wiley & Sons, pp. 3–24. Jahan, A., Edwards, K.L. 2015. A State-of-the-Art Survey on the Influence of Normalization Techniques in Ranking: Improving the Materials Selection Process in Engineering Design. Materials and Design 65, 335–342. Jahan, A., Ismail, M.Y., Sapuan, S.M., Mustapha, F. 2010. Materials Screening and Choosing Methods – A Review. Materials and Design 31, 696–705. Jee, D.-H., Kang, K.-J., 2000. A Method for Optimal Material Selection Aided with Decision Making Theory. Materials and Design 21, 199–206. Pahl, G., Beitz, W., 1996. Engineering Design: A Systematic Approach . Springer-Verlag. Raman, A. 2007. Analysis of Materials Performance Efficiency. Journal of Materials Engineering and Performance 16, 685–693. Rao, R.V. 2006. A Material Selection Model Using Graph Theory and Matrix Approach. Materials Science and Engineering: A 431, 248–255. Shanian, A., Savadogo, O. 2006. A Material Selection Model Based on the Concept of Multiple Attribute Decision Making. Materials and Design 27, 329–337. Sirisalee, P., Ashby, M.F., Parks, G.T., Clarkson, P.J. 2004. Multi-Criteria Material Selection in Engineering Design. Advanced Engineering Materials 6, 84–92. TEMA, 2007. Standards of Tubular Exchanger Manufacturers Association , 9 th ed. Tubular Exchanger Manufacturers Association Inc. Ullman, D.G., 2003. The Mechanical Design Process . McGraw-Hill. 4. Conclusions References Ashby, M.F., 1992. Materials Selection in Mechanical Design . Pergamon Press. Ashby, M.F., 2000. Multi-Objective Optimization in Material Design and Selection. Acta Materialia 48, 359–369.