Optimization of material composition of functionally graded plate for thermal stress relaxation using a genetic algorithm

In this article, a genetic algorithm is applied to an optimization problem of material composition for a plate of step-formed functionally graded mate rials The step-formed functionally graded plate is analyzed as a laminated composite plate made of numerous layers with homogeneous and different isot ropic material properties. First the one-dimensional transient temperature distribution for a laminated plate is analyzed theoretically. In addition, the thermal stress components for such an infinitely long plate are formula ted under the mechanical condition of being traction-free. As a numerical e xample, a plate composed of zirconium oxide and titanium alloy is considere d. In addition, for the optimization problem of minimizing the thermal stre ss distribution, the numerical calculations are made using a genetic algori thm without supposing a distribution function of material composition and t he optimal material composition of each layer is determined taking into acc ount the effect of the temperature dependency of material properties. Furth ermore, the results obtained when a distribution function isn't specified a nd the results found when a distribution function is specified are compared .