Parametric study on longitudinal and out-of-plane compressive properties, progressive damage and failure of 3D five-directional braided composites

The parametric finite element model (FEM) of three-dimensional five-directional (3D5d) braided composites was established by considering the yarn cross-section and the spatial contact between the yarns. The longitudinal and out-of-plane compressive mechanical properties and progressive damage of composites with various parameters were predicted and experimentally verified. As the fiber volume fraction increase, the mechanical performance improve, both in longitudinal and out-of plane direction. With the increase of braiding angle, the longitudinal mechanical properties decrease and the out-of-plane strength decreases while the modulus increases. The stress–strain curves show brittleness and toughness in longitudinal and out-of-plane, respectively. Due to the influence of stress transfer and component contact, damage is more likely to occur at the connection parts of each component.