Optimization of Laminated Composite Structures Using Harmony Search Algorithm

Abstract

A relatively new heuristic method called Harmony Search (HS) is applied in this work for the optimization of laminated composite structures. This seems to be an unexplored application of the method, although it has already been used for the optimization of frame structures. The Harmony Search algorithm, originally developed to deal with continuous variables, is adapted to handle discrete values allowed for thickness and fiber orientation of the laminate plies, being both taken as design variables. The optimization problem presented in this work is concerned on the minimization of weight and deflection of a laminated composite plate under transverse distributed load. The finite element method is used for the linear analysis of the plate. Ply failure and maximum thickness of contiguous plies with the same fiber orientation are the design constraints. The algorithm performance is evaluated in terms of the apparent reliability (or the chance to find the optimum solution in a single optimization) and computational cost (given in terms of the average number of structural analyses required in a single optimization). Results obtained here showed that the performance of the Harmony Search algorithm was better than the genetic algorithm (GA) for solving the problem studied in this work. This indicates that Harmony Search is a promising method for the optimization of laminated composites.