Enhanced toughening in biocomposites by pinning and bridging effects

The excellent mechanical properties of ‘brick-and-mortar’ structure biological materials such as shells, bones, horns have attracted a plenty of theoretical and numerical works to reveal the toughening mechanisms involved. In this work, a mechanical model has been established by taking into account the effects of both bridging and pinning under plane strain deformation. The toughening ratio has been calculated and compared with that with mere bridging effect, which demonstrates that pinning effect makes an enhanced contribution to the toughness of biocomposites. The effect of interfacial shear strength on pinning effect has also been discussed. The obtained results are expected to provide more insights into the toughening mechanisms and the bionic toughening designs.