金属基复合材料微屈服行为的力学分析与试验

摘要

The microyield behavior and stress-strain distribution of short fibre reinforced metal matrix composites（MMCs） were analyzed quantitatively by micromechanics model,FEM model and experiments.The results show that the MMCs＇ microyield behavior likewise accords with Brown-Luken＇s relation approximately with different short fibre volume fractions and distributions.There is stress concentration in the matrix near the short fibre ends during the microyield process.The material parameters such as dislocation density and grain size have significant effect on the equivalent plastic strain but a little effect on the equivalent stress.The influence of short fibre volume fraction,fibre distribution on microyield behavior were analyzed too.%本文采用细观力学计算、有限元分析和试验测试等方法,定量研究了短纤维增强金属基复合材料微屈服过程中应力应变分布和微屈服规律,结果表明不同短纤维分布朝向、体积比的Al2O3-SiO2（sf）/Al-Si复合材料微屈服行为符合Brown-Lukens关系,在增强体短纤维附近存在较大应力集中,晶粒直径、位错密度等材料参数对等效应力影响不大,对等效塑性应变有显著影响,同时分析了增强体短纤维的体积含量和短纤维分布状态对材料微屈服强度的影响。