Robust design optimization of laminated plates under uncertain bounded buckling loads

In this paper, a new systematic approach is suggested for better exploration of given uncertain buckling loads in the problem of optimal designs of hybrid symmetric laminated composites. Laminated composites are made up of 16-layered carbon-epoxy, glass-epoxy, and hybrid carbon-glass plies with discrete ply angles as design variables. In the analysis, the ply angles and the type of constituents in the laminates are varied, and one source of uncertainty, namely, uncertainty in buckling load is incorporated. In order to form nested optimization, a new improved rank-based version of Quantum-inspired Evolutionary Algorithm (QEA) is proposed and different versions of QEA and Genetic Algorithm (GA) are utilized. Using anti-optimization approach, the worst case biaxial compressive loading is obtained by Golden Section Search (GSS) method and the buckling load capacity is maximized. Numerical results of the optimal configurations are obtained under several bi-axial loading cases, panel aspect ratios, and materials. The results are investigated from different perspectives and sensitivity analyses are performed.