Optimal design of blended composite laminate structures using ply drop sequence

In this paper, the concept of ply drop sequence (PDS) is introduced for designing of composite laminate structures with multiple regions. The PDS describes the order of ply-drops from the thickest guide laminate to a series of thinner ones, and further ensures laminate continuity across the entire structure. Comparing with deleting a contiguous innermost/outermost plies in the classical guide-based blending, using PDS is more flexibly of dropping plies between adjacent regions. A fully blended design is represented by a stacking sequence of the guide, a PDS and a thickness distribution over the whole regions of the structure. A genetic algorithm (GA) with special operators and codification is adopted for the PDS-based blending optimization, which guarantees the design is completely blended within the GA iterations. The proposed method is applied to an 18-panel horseshoe benchmark problem to demonstrate its flexibility and potentiality.