基于弹塑性剪滞理论的单丝复合材料段裂过程的蒙特卡罗模拟

Monte Carlo simulation of single fiber composite fragmentation process based on the elastic-plastic shear-lag theory

单丝复合材料段裂试验(SFCFT)中,随着外载荷的增加,纤维出现了随机脆断的现象,并在一定的载荷下纤维的段裂数达到"饱和"状态(即纤维段裂数目不再增加),该试验常用于表征纤维与基体间界面性能。针对该试验,本文中充分考虑了组分材料的真实性能(即基体材料的弹塑性性能),利用弹塑性剪滞理论进行纤维与基体间的应力传递分析,初步获得较真实的纤维轴向应力及界面剪应力分布形式;在此基础上,考虑纤维强度分布的非均匀性,利用蒙特卡罗(Monte Carlo)方法对试验中纤维的随机段裂过程进行了模拟预报,获得载荷与纤维的段裂数的关系。模拟预报与试验结果比较吻合,表明该应力分析及模拟方法的有效性。

In the single fiber composite fragmentation test（SFCFT）,the fiber fragmented randomly with the load increasing and the number of fiber fragments saturated under some load（The number of fiber fragments didn＇t increase）.This test was commonly used to characterize the interfacial property between fiber and matrix.For this test,the stress transfer analysis was done with the elastic-plastic shear-lag theory under the consideration of the real performance of component materials（elastic-plastic of the matrix）.So the more true form of stress distribution in the fiber axial direction and at the interface between fiber/matrix could be obtained.The heterogeneity of fiber strength distribution was considered also and the random fragmentation process in the test was simulated with the method of Monte Carlo based on the analysis of stress transfer.The relationship between load and the number of fiber fragments is forecasted.The anastomosis of result between simulation and test is achieved.So it is manifested that the stress analysis and simulation method are valid.