DAMAGE MECHANISM ANALYSIS OF 2D 1× 1 BRAIDED COMPOSITES UNDER UNIDIRECTIONAL TENSION

Coupling with the periodical displacement boundary condition, a representative volume element （RVE） model is established to simulate the progressive damage behavior of 2D 1×1 braided composites under unidirection- al tension by using the nonlinear finite element method. Tsai-Wu failure criterion with various damage modes and Mises criterion are considered for predicting damage initiation and progression of yarns and matrix. The anisotropic damage model for yarns and the isotropic damage model for matrix are used to simulate the microscopic damage propagation of 2D 1×1 braided composites. Murakami＇s damage tensor is adopted to characterize each damage mode. In the simulation process, the damage mechanisms are revealed and the tensile strength of 2D 1 × 1 braided composites is predicted from the calculated average stress-average strain curve. Numerical results show good agreement with experimental data, thus the proposed simulation method is verified for damage mechanism analysis of 2D braided composites.