Layup optimization for maximum buckling load of variable-stiffness laminates considering manufacturing factors

There are some special issues in manufacturing, modeling and layup optimization for maximum buckling load of variable-stiffness composite laminates compared with traditional ones. Firstly, the manufacturing factors which need to be considered when designing variable-stiffness laminates were summarized and the design requirements for buckling were proposed. Secondly, two modelling methods were developed, namely the ideal model and the model considering the tow width. An automatic parametric modeling program was written based on the secondary development of ABAQUS. Buckling analysis was carried on a series of variable-stiffness plates with different ply angles, and the restriction of the minimum curvature radius was discussed and the reasons for the increase in the buckling performance of variable-stiffness laminates were explained. Based on the mechanism of increasing buckling load, a layup optimization method to maximize the buckling load of variable-stiffness laminates was created and the optimum layup was obtained using a two-step genetic algorithm. Finally, the tow width and ply staggering effects on the layup optimization for maximum buckling load were investigated using the model considering the tow width. The result demonstrates that it is generally feasible to apply the simplified ideal model when carrying out the layup optimization for maximum buckling load of variable-stiffness laminates. Considering the manufacturing factors, the optimum variable-stiffness plate increases the buckling load dramatically compared with the traditional one.