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.