Genetic algorithm representations for laminate layups

The design of laminate layups using a genetic algorithm (GA) search-based function optimizer has been investigated using both a generate-and-test evaluation function and the layup-synthesis rule-base from a knowledge based design system. (The small rule-base from the laminate design was translated into a procedural evaluation function which could be called by the GA.) A simple coding of plies to genes is shown to be applicable in each case, but only when coupled with a penalty function which constrains genetic search to permissible layup candidates. Two experiments have been performed: a comparison of the GA search algorithm with a random/greedy search algorithm and a comparison of the GA with a rule based design system. Comparative tests with the rule based laminate design system are presented for four different load types. These demonstrate the robustness and accuracy of the system for the design of small scale asymmetric laminates.