Effects of fiber-matrix deboning matrix cracking on mechanical properties of composite laminates using micromechanical approach

Fiber reinforced composites are likely to fail under transverse tension. Matrix cracking and fiber-matrix debonding are two failure mechanisms observed firstly in most cases. These mechanisms are interacting with each other in a way that partial debondings at fibre-matrix interfaces can joint to form matrix cracks. For the sake of simplicity, matrix cracking and fiber-matrix debonding have been studied separately to date. In the present study the combine effect of both mechanisms is studied. To achieve this, matrix cracking is modeled in micromechanics framework based on unit cell concept using FEM. Debonding at fibre-matrix interfaces is then considered using cohesive zone modeling (CZM); thereafter the interaction between both mechanisms is studied. With the results obtained from this new developed model, the damage share of each mechanism is determined. The obtained stiffness reduction and energy release rate are also compared in the absence and presence of fiber-matrix debonding.