A method for optimally designing laminated plates subject to fatigue loads for minimum weight using a cumulative damage constraint

Abstract

A procedure to optimally design laminated plates for a specific cyclic life using a cumulative damage constraint is described. The objective is minimum weight, and the design variables are the fiber orientation, and the plate thickness. The plates are subjected to cyclic bending loads, and the finite element method, in conjunction with the Golden Section method, is used to determine the design variables optimally. The FE formulation is based on Mindlin theory for moderately thick laminated plates and shells, and the formulation includes bending–twisting coupling. In order to demonstrate the procedure, several plates with differing events, load magnitudes and type, aspect ratios, boundary conditions and cyclic lives are optimised, and compared.