In situ strength analysis of cross-ply composite laminates containing defects and interleaved woven layer using a computational micromechanics approach

The transverse strength of 90° plies located in cross-ply laminates subjected to transverse tension is investigated numerically. To reach this aim, it is assumed that the transverse cracking is formed by coalescence of fiber–matrix debonding, which propagates along the planes parallel to the fibers. The two-dimensional finite element model (FEM) investigates the dominant micromechanical damage mechanisms, fiber–matrix debonding, and matrix cracking using the cohesive zone model (CZM) and plasticity, respectively. The numerical simulation is according to the extended computational micromechanics (ECMM) approach, which can be applied as a useful virtual test method instead of performing costly characterization tests. The results obtained from the present study show that the defects such as voids, imperfections, and residual stresses contribute to reducing the in situ strength of 90° plies. In the case of using an interleaved woven layer, the formation of the first transverse crack in unit cells within 90° layer is delayed.