Optimum design of composite structures with ply drop using genetic algorithm and expert system shell

A patchwise optimal layup design method is developed for the tapered composite laminates in this paper. In the patchwise layup design method, the optimal solution is obtained by integration of an expert system shell, genetic algorithm (GA) and finite element method. In this approach, the weight of composite laminates with ply drop under strength constraint is minimized and for this purpose, stacking sequences and the number of plies are optimized. The design variables are the discrete ply angles such as 0 degrees, +/- 45 degrees, and 90 degrees and the number of plies in each patch. The patchwise designed composite laminates are compared with the uniform thickness laminates. It shows that the optimized layup can considerably reduce total weight of the composite laminates. (C) 1999 Elsevier Science Ltd. All rights reserved.