Bioinspired design optimization for pseudo-ductility in platelet fibre laminates

Platelet designs inspired by nacre shell microstructure are a novel approach to confer pseudo-ductile deformation properties to brittle fibre reinforced polymer laminates while retaining high stiffness and strength. Here we present an experimental and finite element modelling study to investigate the effects of tiling pattern, overlapping length and interlaminar toughness of the ply platelets on the tensile properties, pseudo-ductility, and failure modes of platelet laminates inspired by nacre. The findings are then used to optimize the design for maximal pseudo-ductility for a given tensile strength. Experimental results show that unidirectional platelet laminates can possess tensile strengths in excess of 1 GPa while pseudo-ductile deformation accounts for more than ∼ 50% of the ultimate failure strain. Finite element modelling of platelet laminates reveals that the amount of pseudo-ductility can be tailored via the design optimization of the tiling pattern, overlap length, composite thickness and mode II interlaminar toughness of the platelets. The mechanisms controlling the pseudo-ductility effect in the bioinspired platelet laminates is described.