MODELING OF FRACTURE IN BIO-INSPIRED MATERIALS

Abstract

Nacre (mother of pearl), bone, and teeth boast a prominent amalgamation of mechanical facets such as strength, toughness and sti ness. Merger of these properties in engineering materials is still a challenge. Nacre, which is an inner shell layer of many sea-shells, primarily made of 95% of brittle mineral (calcium carbonate), however; it exhibits superior mechanical properties as compared to their major constituents. Micro-structure of nacreous layer reveals the staggered 'brick-bridge-mortar' architecture in which polygonal shaped mineral tablets are stacked and organic layer and mineral bridges act as a glue and interconnection between platelets, respectively. Mimicking of the architecture of these biological materials has captured the attention of research community for development of high performance composites. However, an in-depth knowledge of structure-propertiesfunction relationship is still lacking. Therefore, the goal of the present study is to provide a detailed understanding on the role of geometric parameters towards the origin of extraordinary mechanical properties. In this work, we will investigate the mechanical behavior of staggered architecture using nite element framework under quasi-static loading condition. The fracture of staggered composite will be simulated using a continuous cohesive zone models accounting the failure of inter-layers and mineral bridges. In this study we will decode the complicated inter-relation between geometrical features and material properties. This study will also provide a parametric understanding of geometrical features such as overlap ratio, aspect ratio, bridge density and bridge distribution on emergent strength, sti ness and toughness. Finally, detail design map will be constructed that will assist to develop novel architectured composites with tailored mechanical properties.