COMPOSITE DESIGN AND OPTIMIZATION THROUGH BIOMIMICRY

Abstract

Inspired by the exoskeletal structure of crustaceans, study was undertaken to investigate the failure mechanism, optimization and application of helicoidal laminates. The optimal helicoidal configuration can significantly improve the out-of-plane loading performance of the laminate. Fiber breakage/delamination and spiraling matrix split are the two damage mechanisms in helicoidal laminates which is dictated by the structure and material properties, the optimal helicoidal laminate always experiences a mix of the two. This study further investigates the natural helicoidal laminates and discovered their inter-ply angle changes gradually from small angles close to the surface of loading to large angles further in. It is proven by experiments and numerical simulations that such structure is most effective. This study also designed helicoidally stacked healable laminates that are able to regain their strength after failure, as helicoidal laminates can be controlled to minimize fiber damage which leads to outstanding healing capabilities. Investigations on the ballistic performance of helicoidal laminates were then conducted through experiments and simulations. It is found that the helicoidal laminates with small inter-ply angles lead to spiraling matrix split during impact in preference to fiber breakage. This is effective for improving the ballistic performance of brittle laminates but less effective for tougher laminates.