Quasi-brittle fracture of heterogeneous materials: a nonlocal damage model

摘要

A time-dependent nonlocal continuous damage model is developped in order to describe the transition to failure in quasi-brittle materials. It is based on an energetic approach and takes into account the interactions between microstructural elements through an integral nonlocal formulation in which a microscopic length is included. Using a phase-field approach, the damage evolution law of each point of the system is obtained. The model is applied to a fiber bundle and we study the influence of the internal length on the temporal and spatial organization of damage prior to complete failure. This model captures qualitatively various features of quasi-brittle fracture as observed in experiments and allows for a rigorous analysis of the energy dissipated during the failure process.