Investigation of the effective properties of 3-D braided composites with flaws by the finite element method based on nonhomogeneous elements

In this paper the effective mechanical property of a type of 3-D braided composites with flaws is studied. A representative element model for the 3-D braided composites is built. The nonhomogeneous finite element method is adopted to calculate the stress distributions. The modulus and the Poisson ratio of the 3-D braided composites with flaws are obtained. The results are compared with those of the 3-D braided composites without flaws. It is shown that the present method is very effective for the studying the effective properties of 3-D braided composite materials with complex material distribution and flaws. It is found that the flaws may weaken the mechanical property of the 3-D braided composites but the influences on the components of the mechanical property of 3-D braided composites are different.