Application of Genetic Algorithm for the Optimal Lay-up of Plates made of Composite Laminates

摘要

Laminated composite structures are finding wide range of applications in many branches of technology. They are much suited for weight sensitive structures (like aircraft) where thinner and lighter members made of advanced fibre reinforced composite materials are used. The orientations of fibre direction in layers and number of layers of composites play a major role in determining the strength and stiffness. Thus the basic design problem is to determine the optimum stacking sequence of the composite laminate. Many methods are available at present for the design optimization of structural systems and these methods assume that the design variables are continuous. In this paper a different search and optimization algorithm, known as Genetic Algorithm (GA) has been successfully applied to obtain optimal fibre orientation of multi-layered composite plates, which considers the angle of fibre orientation as a discrete variable. The GA combines Darwinian principle of survival of the fittest and structural information exchange using randomized operators to evolve an efficient search mechanism avoiding local minimum. The Simple Genetic Algorithm is mainly based on three operators namely Reproduction, Crossover and Mutation. Plates composing of two to nine layers without stiffener, with one stiffener & with two stiffeners for single material as well as different materials were analysed and the maximum frequency for each population is computed using the software FEAST-C.