Optimal design of symmetric laminates with cut-outs for maximum buckling load

Finite element solutions are presented for the optimal design of symmetrically laminated rectangular plates with central circular cut-outs subject to a combination of simply supported, clamped and free boundary conditions. The design objective is the maximisation of the biaxial buckling load by determining the fibre orientations optimally with the effects of bending-twisting coupling taken into account. The finite element method coupled with an optimisation routine is employed in analysing and optimising the laminated plate designs. The effect of plate size and boundary conditions on the optimal ply angles and the buckling load are numerically studied, and these results are compared to those from an article which appeared in this journal in 1996; viz, plates without cut-outs (Walker M, Adali S, Verijenko VE. Optimisation of symmetric laminates for maximum buckling load including the effects of bending-twisting coupling. Computers and Structures 1996; 58: 313-19). (C) 1998 Elsevier Science Ltd. All rights reserved.