Optimization of laminated composite plates subjected to nonuniform thermal loads

Fiber-reinforced laminated composite structures are extensively used in aircraft and aerospace industries for their high specific strength and stiffness. In such applications, they are generally subjected to nonuniform thermal loads due to change in thermal conditions. Therefore, the composite structures used in the applications in which they are subjected to nonuniform thermal loads must also be designed to withstand thermal loads. As mechanical and thermal properties of fiber-reinforced laminated composites are greatly influenced by the direction of fibers and stacking sequences, they are optimally varied in this article to maximize the critical buckling temperature of the composite plate. The ply angle and stacking sequence of the laminated composite plate are optimized using genetic algorithm to maximize the thermal buckling temperature. As the plate is subjected to different kinds of nonuniform thermal load cases, finite element technique is used to analyze the plate during the optimization process. As geometry and supporting conditions of the plate also have great influence on its thermal buckling strength, the investigation is further widened by carrying out the optimization process for the plate model constructed with various types of support conditions, aspect ratio, and nonuniform load cases. The numerical results clearly show the necessities that the optimum ply angle and stacking sequences are greatly varying based on the aspect ratio, support conditions, and nonuniform loading cases.