An approach for testing and predicting longitudinal tensile modulus of 3D braided composites

Three-dimensional braided composites have a skin-core structure and can be divided into three kinds of regions: interior, surface, and corner, which have different mechanical properties. Based on the structure characteristics and stiffness average volume formula, a new approach for testing and predicting longitudinal tensile modulus of three-dimensional braided composites is proposed in this paper. This approach can not only provide a basis to establish test standard for three-dimensional braided composites but also predict the longitudinal tensile modulus of three-dimensional braided composites. It is verified by an application example. Additionally, the effects of the number of rows and columns of yarns in preforms on longitudinal tensile modulus of three-dimensional braided composites are discussed here.