含共晶界面陶瓷复合材料的损伤应变场分析

摘要

研究了含共晶界面陶瓷复合材料的损伤应变场及其尺度效应。根据含共晶界面复合陶瓷的细观结构特性，利用含共晶界面陶瓷复合材料中三相胞元内的应力场分布规律，得出棒状共晶体内的无损应变场分布规律。针对棒状共晶体内存在损伤的现象，通过引入损伤变量，利用三相模型法得到了棒状共晶体内存在损伤时的应变场分布规律；根据应变和纤维状夹杂直径之间的关系，分析了棒状共晶体内的损伤应变场及其尺度效应。结果表明，含共晶界面陶瓷复合材料内三相胞元中基体、界面相和纤维夹杂内的损伤应变场对纤维夹杂直径具有明显的尺度效应。%The size dependent damage strain distribution of eutectic composite ceramic with eutectic inter- phase is studied. By the micro-structure characteristics of composite ceramic with eutectic interphase,the local stress field distribution of three-phase element in eutectic composite ceramics is suggested to deter- mine the local strain field distribution of the eutectic rod. The emerging cause of damage behavior of the eutectic ceramic rod is interpreted and damage variables is accounted for determining the local strain field distribution of the eutectic rod with damage behavior by using three-phase model method. On the basis of the relation between local strain field and fiber diameter, the size dependent damage strain field of the eutectic ceramic rod is analyzed. The results show that the damage strain fields in matrix, interphases and fiber of eutectic composite ceramics with eutectic interphase are dependent on the diameter of fibers.