金属基复合材料单向和循环变形行为的数值模拟研究

A NUMERICAL STUDY OF TENSILE AND CYCLIC DEFORMATION BEHAVIOR OF METAL MATRIX COMPOSITES

利用晶体细观力学模型，依据组元材料的单晶体变形性质、以Ａｌ－Ａｌ２Ｃｕ自生复合材料为模型材料，用数值法模拟其拉伸和循环拉伸变形过程，得到了与有关实验结果相符的应力－应变曲线，研究了增强相间距和循环加载过程对复合材料变形行为的影响，通过考察变形过程中组元相及其界面的应力分布规律，分析研究了循环变形过程中基体Ｂａｕｓｃｈｉｎｇｅｒ效应对于复合材料微观变形与损伤机制的作用．结果表明，晶体细观力学模拟计算能够定量地细致反映组元材料性质和分布以及加载路径等因素对金属基复合材料宏观力学性能及局部变形不均匀特性的影响，为有关变形的实验研究及相应的材料设计提供了可靠的理论依据和定量表征．

A crystalline micromechanical approach is developed to study the mechanical behavior of metal matrix composites numerically, on the hosts of the data of single crystal deformation.The tensile and cyclic tensile deformation is simulated in Particular using a model system Al-A12Cu in-situ composites. The calculated stress-strain curves agree well with the experimental results given by Davidson et al. The distribution and varistion of internal stresses in the specimens are obtained.The dependence of the deformation behavior of metal matrix composites on interlamellar spacing λand loading path is investigated. The influence of the matririx's Bauschinger effect is analyzed.The effect of matrix and reinforcement and especially interface area on both tensile and cyclic deformation mechanism of metal matrix composites is discussed. It is shown, the crystalline microme micromechanical approach, which can provide some useful informations to insigt into the deformation mechanism, is very helpful to the analysis and design of the mechanical properties of metal matrix composites.