Multi-Objective Optimisation of Orthogonally Tophat-Stiffened Composite Laminated Plates

This paper deals with the multi-objective optimisation of an orthogonally tophat-stiffened composite laminated plate. The plate is simply supported around all its edges and subjected to a uniform lateral pressure load. Genetic algorithm (GA) technique is employed as the optimisation tool. As objective functions, both structure weight and manufacturing cost, with respect to a set of practical stiffness and strength constraints (maximum stress criterion), are considered. Structural analysis of the plate is performed using a combination of elastic grillage solutions and an equivalent elastic property approach. Through the unique solutions in conjunction with the GA, it is possible to produce layer by layer optimisation results for the laminated plate, the web, the crown and the overlaminate of the plate. Therefore, the present optimisation framework is capable of dealing with a large number of design variables such as different fibre materials, fibre volume fractions, fibre orientations and geometric values.