Robust optimum designs of fibre-reinforced composites with design-variable and non-design-variable uncertainties

Abstract

An innovative optimum design method of fibre-reinforced composite considering both design-variable and non-design-variable uncertainties is proposed in this article. By including the sensitivities and uncertainties in the modified constraints, a robust optimum design problem is formulated, which takes care the effects of non-design-variable and design-variable uncertainties by a maximizing procedure. The optimization and anti-optimization subproblems are both numerically solved in traditional anti-optimization technique. The anti-optimization subproblem is analytically solved in the proposed method hence it is more efficient in computing time than traditional anti-optimization technique. The accuracy of the proposed method was verified by examples having analytical solution. Besides design-variable uncertainties such as ply orientation and ply thickness uncertainties, the effects of non-design-variable uncertainties such as material property uncertainties on optimal weight of composite plate were studied in the illustrated examples. It is found that the optimal weight increases with uncertainties and the thermal buckling and stress concentration problems have the most significant effects of uncertainties among the studied examples.