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.