Stress and failure analysis of 3D orthogonal interlock woven composites

A three-dimensional woven composite strength model is presented for predicting the failure behavior of three-dimensional orthogonal interlock woven composites under on-axis uniaxial static tensile loading and shear loading. The model is based on two-level discretization of the repeating unit cell. The repeating unit cell is discretized into sections, elements, subsections and subelements. The model predicts the stress levels at which the secondary failures take place at subelement level. The effect of secondary failure is considered for further analysis and the ultimate tensile strength and shear strength and the corresponding strains are predicted. A parametric study has been carried out for different 3D orthogonal interlock woven composite configurations. In general, it is seen that there is no significant reduction in the inplane elastic and strength properties for 3D orthogonal woven composites, compared to the corresponding cross-ply laminates made of unidirectional layers, but there is a significant increase in the through-the-thickness properties.