Prediction on in-plane tension Young's modulus of braided composites with pore matrix

Predicting elastic properties of braided composites is useful in aerospace structures. In order to predict the properties precisely, fiber undulation and pores in the matrix must be considered during the calculation process. For pores in the matrix, they are considered as inclusions in a kind of isotropic material. Based on inclusion theory, the Mori-Tanaka method is used to predict Young's modulus of the pore matrix. Stiffness averaging method gives the estimated value of Young's modulus of the fiber parallel to the loading direction which contains undulation. Finally, the effective Young's modulus of the representative volume element (RVE) are obtained according to the mixture formula. In order to facilitate the finite element calculation, the RVE is divided into three kinds of sub unit cells. Finite element models of the three kinds of cells are established. And elements representing pores are used in the finite element models based on Python language. The error between analytical method and finite element method is small, which gives an excellent prediction on inplane tension Young's modulus of braided composites.