摘要
纤维氧化会使C/SiC复合材料的强度大幅度降低,原因是纤维中出现了缺口,不仅仅产生应力集中,而且纤维强度大大降低,纤维很容易发生断裂。文中基于这一损伤机理,建立细观力学分析模型,运用统计强度理论,对C/SiC复合材料无应力氧化残余强度进行模拟计算。模型引入纤维的氧化缺口,并考虑纤维特征强度的降低,获得与氧化试验值比较一致的模拟结果,表明模型的合理性。
The oxidation of fibers may cause significant strength decline in C/SiC composites as a result of the notches produced in the oxidizing process,which not only induce stress concentration but also result in fiber strength degradation.Both the above reasons will enhance the fiber failure probability within the notch length.Based on this damage mechanism and the statistic theory,a micromechanics based model is established for oxidation residual strength calculation.The fiber notch is introduced and the fiber characteristic strength degradation is considered.However,the effect of stress concentration is neglected.The values obtained from the model are in excellent agreement with the data derived from the non-stress oxidation experiments.This indicates the reliability of the analytical model.
出处
《机械强度》
CAS
CSCD
北大核心
2011年第1期106-110,共5页
Journal of Mechanical Strength
基金
国家自然科学基金资助项目(90405015)~~
关键词
C/SIC复合材料
氧化
特征强度
细观力学
残余强度
C/SiC composites
Oxidation
Characteristic strength
Micromechanics
Residual strength
