Differential Evolution on the Minimization of Thermal Residual Stresses in Functionally Graded Structures
Global optimization techniques present considerable advantages when applied to non-linear and/or non-convex design spaces, where local search techniques can easily be trapped in local minima. In the present work, it is considered the application of Differ
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Differential Evolution on the Minimization of Thermal Residual Stresses in Functionally Graded Structures T.A.N. Silva and M.A.R. Loja
Abstract Global optimization techniques present considerable advantages when applied to non-linear and/or non-convex design spaces, where local search techniques can easily be trapped in local minima. In the present work, it is considered the application of Differential Evolution to the optimization of thermal residual stresses distribution in a sandwich panel, which is composed by an aluminium core and functionally graded outer layers. With this aim, numerical examples were carried out in order to evaluate the influence of different design parameters on the thermal residual stresses distribution. From those results, it is possible to conclude from the adequacy of the Differential Evolution strategy to minimize thermal residual stresses values, under different scenarios. It is worth to note the obtained increasing smoothness of residual stresses distribution, specially on the material transition interface. Keywords Functionally graded material • Residual stresses optimization • Differential evolution
T.A.N. Silva (*) ADEM/ISEL– Instituto Superior de Engenharia de Lisboa, Av. Conselheiro Emı´dio Navarro, 1, 1959-007 Lisboa, Portugal e-mail: [email protected] M.A.R. Loja IDMEC/LAETA – Instituto de Engenharia Mecaˆnica, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal e-mail: [email protected] A. Madureira et al. (eds.), Computational Intelligence and Decision Making: Trends and 289 Applications, Intelligent Systems, Control and Automation: Science and Engineering 61, DOI 10.1007/978-94-007-4722-7_27, # Springer Science+Business Media Dordrecht 2013
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T.A.N. Silva and M.A.R. Loja
Introduction
Dual-phase functionally graded materials (FGM) are a particular type of composite materials, whose properties are tailored to vary continuously, depending on the composition distribution of its two constituents, and which use is increasing on the most diverse application fields. These materials are known to provide superior thermal and mechanical performances when compared to the traditional laminated composites, because of its continuous properties variation characteristic, which enables among other advantages smoother stresses distribution profiles. Moreover, it is well known that abrupt transitions in material properties within a composite structure can cause stress concentrations, which can be mitigated by gradually varying the microstructure and/or composition of materials in a gradient architecture [1]. The concept of FGM emerged in the 1980s [2, 3]. Since then, one can conclude of a great research involvement on the study of these materials. In fact one of the significant capabilities of these materials are related to their behaviour in high temperature conditions, thus being initially thought as thermal barriers [4]. Birman and Byrd [5] presented a work where the principal developments in FGMs are focused. Diverse areas relevant to various aspects of theory and
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