含脱粘界面颗粒增强金属基复合材料局部应力场的尺度效应

The Size Effect of Local Stress Field in PRA with Interphase Debonding

在通过三相胞元方法求解出的复合材料有效刚度基础上,将三相胞元置于有效介质氛围中,且有效介质与复合材料具有相同弹性常数;根据有效自洽理论对受单轴拉应力作用的复合材料进行局部应力场分析,理论结果表明：只有考虑存在脱粘界面时,颗粒增强复合材料局部应力场具有明显的尺度效应,其应力值还与脱粘界面含量有关;基体承载的应力要小于外载应力,颗粒内纵向应力要大于外载荷,对基体材料起到了强化的作用,这与实际情况相符合。

Based on the effective stiffness costants solved by the three-phase-cell-method,the three-phase-cell is set in the effective medium and the elastic constants of the effective medium are the same with the composite.According to the effective self-consistent-method,the local stresses under the uniaxial stress are analyzed and the theoretical results show that considering the interphase debonding,the composite has visible scale effect and the stresses relate to the content of debonding;that the longitudinal stress in matrix is less than the external load,whereas the stress in particle is more,so the metal matrix is reinforced.