Micro/meso-scale damage analysis of a 2.5D woven composite including fiber undulation and in-situ effect

A micro/meso-scale analysis framework is proposed here, to investigate the deformation and failure of a 2.5D woven composite subjected to tensile loading. The elasticity and strength of fiber bundles are predicted by the micro-scale analysis with consideration of the fiber undulation effect and the in-situ effect. In the meso-scale analysis, a voxel-based representative volume element model is developed to simulate the damage within fiber bundles and pure matrix, and validated with experimental results. It is found that the stress–strain curve in the weft direction maintains approximate linear, while the stress–strain curve in the warp direction presents a nonlinear behavior. The fiber undulation effect decreases the effective stiffness and strength of woven composites in the weft tension. The in-situ effect delays the transverse tensile damage initiation, resulting in the weaker nonlinearity of stress–strain curves in the warp and weft tension. The influence of shear coupling coefficient in the failure criterion on the mechanical response is also discussed through numerical parameter study.