Modeling damages and cracks growth in composite with a 3D discrete element method

This paper presents a 3D simulation of damages and cracks growth in composite material using Discrete Element Method (DEM). Fiber/matrix debonding and ply to ply delamination, cracks matrix, rupture of fibers are addressed. Matrix and fiber are supposed to be brittle materials and follow a linear fracture model. Cohesive contact laws are implemented to model interfaces behavior for both debonding (fiber/ matrix) and delamination (ply/ply). Piecewise linear elastic laws usually used in cohesive zone models are retained in this work. A Double Cantiliver Beam (DCB) test is first experimented using the present DEM with Cohesive Contact Models (CCM). Then, based on De Borst's works [1], a single fiber composite under transverse traction is modeled to study debonding and matrix cracks propagations depending on the matrix and the fiber/matrix interface strengths ratio. A bi-disperse medium for matrix and fiber is specifically elaborated to reduce the discrete elements number. The analysis is extended to a so-called multi-fibers composite specimen, also called Statistical Elementary Volume (SEV), made of several fibers embedded in the matrix. Finally, the results are compared with DeBorst's works and qualitatively discussed. (C) 2016 Elsevier Ltd. All rights reserved.