多尺度模拟SiC/IMI834复合材料失效

The multisale model of the failure in SiC/IMI834 composites

基于格林函数和有限元分析的多尺度方法模拟SiC/IMI834复合材料拉伸试验,研究复合材料微区应力分布、宏观力学性能和纤维失效情况。其中有限元分析用来计算SiC/IMI834复合材料微区应力分布并为格林函数提供应力传递集中因子。格林函数用来模拟SiC/IMI834复合材料宏观失效过程及力学性能。结果表明,失效纤维上应力恢复区长度受材料性能影响,与外加载荷无关;距离失效纤维越远,沿失效端面纤维上轴向应力越低;距离失效纤维越近,沿失效端面基体上轴向应力越低;SiC/IMI834复合材料宏观失效应变随纤维体积分数增加而提高,但SiC/IMI834复合材料初始纤维失效与纤维体积分数无关,拉伸应变均为0.01。

Green＇s function and finite element methods were used to model the tensile test of metal matrix composites,and research the micro-stress distribution,macro-mechanical properties,and fiber failure in metal matrix composites.Finite element method was used to calculate the micro-stress field and stress transfer concentration factor for Green＇s function.Green＇s function was used to simulate the macroscopic failure process and mechanical properties in metal matrix composites.The results are shown that the stress recovery length in failure fiber depends on material properties,but is independent of the applied load.The axial stress in fiber along the failure surface diminishes as the distance from the failure fiber increases.However,the axial stress in matrix along the failure surface decreases as the distance from the failure fiber decreases.The macroscopic failure strain in SiC/IMI834 composites increases with the increasing of fiber volume fraction.However,the initial failure fiber in SiC/IMI834 composites has nothing to do with the fiber volume fraction.