Cut-edge is a kind of damage for the three-dimensional four-directional (3D4d) braided composites which is inevitable because of machining to meet requisite shape and working in the abominable environment. The longitudinal tensile experiment of the 3D4d braided composites with different braiding angles between cut-edge and the ones without cut-edge was conducted. Then representative volume cell (RVC) with interface zones was established to analyze the tensile properties through the fracture and damage mechanics. The periodic boundary conditions under the cut-edge and uncut-edge conditions were imposed to simulate the failure mechanism. Stress-strain distribution and the damage evolution nephogram in cut-edge condition were conducted. Numerical results were coincident with the experimental results. Finally the variation of cut-edge effect with the specimen thickness was simulated by superimposing inner cells. The consequence showed that thickness increase can effectively reduce cut-edge influence on longitudinal strength for 3D4d braided composites. Cut-edge simulation of braided composites has guiding significance on the actual engineering application.

在对三维四向（3D4d）编织复合材料进行机加工以达到所需的形状以及在恶劣的环境中工作情况下，切边是一种不可避免的损伤。进行了具有不同的编织角度的有切边和无切边的3D4d编织复合材料的纵向拉伸实验。然后建立具有界面区域的代表性体积单元（RVC），并通过断裂和损伤力学分析拉伸性能。在有切边和无切边条件下施加了周期性边界条件来模拟失效机理。得到了有切边条件下的应力-应变分布和损伤演化云图。数值结果与实验结果一致。最后，通过叠加内部单元来模拟切边效应随试件厚度的变化。结果表明，增加厚度可以有效地减少切边对3D4d编织复合材料纵向强度的影响。对三维编织复合材料的切边仿真对实际工程应用具有指导意义。