三维四向大编织角复合材料的细观强度分析

编织角是影响三维编织复合材料力学性能的最重要因素.实验数据表明:大编织角复合材料在单向拉伸作用下的破坏形式较为复杂,其应力-应变曲线呈现非线性特性.本文建立了细观应力场的均匀化列式和有限元求解方法,运用该方法对三维大编织角复合材料的细观应力分布进行了数值模拟,结合相关的强度理论对材料进行失效分析,并进一步对材料的拉伸强度进行预测.强度计算结果与实验结果较为吻合.

Micro Strength Analysis of 3D 4-Directional Braided Composites with Large Braiding Angle

Braiding angle is the most important parameter to impact on mechanical properties of 3D braided composites.The experiment results show that composites with large braiding angle have complex crack forms under uniaxial tensile loading and the tensile stress-strain curves take on nonlinear characters.In this paper,the homogenization formulation of the micro-stress,and the schemes to solve the problem using finite element method were given.The micro-stress distribution of three-dimensional braided composites with large braiding angle was simulated by this method.Proper criteria of strength were used to analyze the failure of the structure,and the tensile strength of the structure was predicted.The calculated results of the strength agree quite well with the experimental results.