Investigation of parameterized braiding parameters and loading directions on compressive behavior and failure mechanism of 3D four-directional braided composites

Three-dimensional (3D) braided composites have been witnessed outstanding advances in structural applications in the past few decades. Herein we established parameterized finite element model to characterize, on a mesoscopic scale, the compressive behaviors of 3D braided composites where the relative displacement boundary conditions were applied, and the cross-sectional extrusion and realistic spatial architecture among braiding yarns were considered. Moreover, the associated relationships between damage evolution and strength prediction and different loading directions, braiding angles and fiber volume fraction, were then thoroughly investigated. The damage evolution was evaluated quantitatively based on continuous damage mechanics. The main damage and failure patterns of the yarn and matrix were presented. The results convincingly concluded that the compressive behaviors remarkably depended on the braiding angle, fiber volume fraction, and loading direction. The numerical stress–strain responses agreed well with the experimental, proving that stiffness degradation and failure strength could be predicted accurately using the established model.