Discrete element modeling of interface debonding behavior in composite material: Application to a fragmentation test

This paper presents a 3D simulation of interface debonding in composite material using 3D Discrete Element Model (DEM). The simulation is based on the experimental results obtained by Guillebaud-Bonnafous and al. Bonnafous2012. A single fragmentation testing of an singer impregnated hemp yarn embedded into a epoxy matrix was investigated. In DEM, matrix and yarn are supposed to be brittle materials and follow a linear fracture model. The discrete elements of matrix are connected by the cohesive beams whereas the one of yarn are connected by the spring links. The cohesive contact laws are implemented to model interface debonding between yarn and matrix (yarn/matrix). Piecewise linear elastic laws usually used in Cohesive Zone Models are retained in this work. The numerical results obtained by DEM are compared with experiment data and finite element modeling on the stress–strain curve and the fragmentation process in yarn during the test. This comparison allows to validate the models used in DEM. To reduce the discrete elements number and save computational time, the bi-disperse medium in DEM for matrix and yarn is specifically elaborated in this study