Multi-directional compression behaviors and failure mechanisms of 3D orthogonal woven composites: Parametric modeling and strength prediction

Three-dimensional orthogonal woven composites (3DOWCs) are extensively adopted in various civil and military fields. Parametric finite element models of 3DOWCs were established based on the mesoscale method to predict the compression strength and progressive damage process. The effects of structural parameters and loading directions on the failure mechanisms were investigated. The predicted results agreed well with the experimental data. The results revealed that yarn densities and loading directions significantly influenced the compression strength. It increased as yarn densities increased, and the weft compression strength was almost the largest in all directions and reached the maximum value of 634.8 MPa. In this case, it was 16.9% and 166.9% higher than that of the warp and Z-directions. Damage evolutions demonstrated that the damage of yarns and matrix occurred separately at the intersection of yarns and yarns, and yarns and matrix. The damage patterns of small warp and large weft yarn densities composites included yarn buckling, the interfacial debonding between yarns and matrix, and matrix cracking. Yarn kinking and fracture were the two main damage patterns of large warp and small weft yarn densities composites, while composites with large warp and large weft yarn densities were more prone to matrix cracking.