Crack sensitivity of nacre-like laminate composite materials: Monte Carlo simulation based on stability theory

Studying the cracking process of nacre is critical for understanding its toughening mechanisms. There are certain challenges in using the conventional fracture mechanics based on a deterministic concept for reproducing the complicated cracking phenomena in nacre. From the perspective of stability analysis, we present an energy-based Monte Carlo (MC) method to search the energy minimum configuration in the kinematically admissible deformation field. Three types of deformation mechanisms and the randomness implemented in MC algorithm coordinate well with system's stability evolutions. We investigated the effect of aspect ratio, tensile and shear deformation of soft phase on the cracking mode transition. Three characteristic cracking modes of crack branching, unlocalized cracking, and independent crack propagation, are found with the adjustment of these parameters. Two of these cracking modes exhibit apparent crack insensitivity. The inner mechanisms of these cracking modes and the crack sensitivity are discussed from the view of material stability. This study offers a new insight and numerical method into the cracking propagation of nacre-like laminate composite materials, and gives some new explanations about the crack sensitivity of these characteristic cracking modes. (C) 2020 Elsevier Ltd. All rights reserved.