增强相/夹杂内螺位错偶极子与含共焦钝裂纹椭圆夹杂的干涉效应

运用弹性力学的复势方法，研究了纵向剪切下增强相/夹杂内螺型位错偶极子与含共焦钝裂纹椭圆夹杂的干涉效应，得到了该问题复势函数的封闭形式解答，由此推导出了夹杂区域的应力场、作用在螺型位错偶极子中心的像力和像力偶矩以及裂纹尖端应力强度因子级数形式解。并分析了位错偶极子倾角 、钝裂纹尺寸和材料常数对位错像力、像力偶矩以及应力强度因子的影响。数值计算结果表明：位错像力、像力偶矩以及应力强度因子均随位错偶极子倾角做周期变化；夹杂内部的椭圆钝裂纹明显增强了硬基体对位错的排斥，减弱了软基体对位错的吸引，且对于硬夹杂，位错出现了一个不稳定平衡位置，该平衡位置随钝裂纹曲率的增大不断向界面靠近；变化 值将出现改变位错偶极子对应力强度因子作用方向的临界值。

INTERACTION BETWEEN A SCREW DIPOLE IN INHOMOGENEITY/REINFORCED PHASE AND A CONFOCAL BLUNT CRACK IN ELLIPTICAL INHOMOGENEITY

By using the complex variable method of Elasticity, the interaction between a screw dipole inside the Inhomogeneity/Reinforced Phase and a confocal blunt crack in elastic elliptical inhomogeneity is investigated and the closed solutions are obtained for this problem. The stress field of inhomogeneity, the image force and image torque acting on the center of screw dipole, the stress intensity factor of the blunt crack tip are obtained in the series form. Simultaneously, the influence law of the dip angle of screw dipole , the size of blunt crack and the material parameters on them are analyzed. The numerical results show that the image force, image torque and stress intensity changes periodically with the dip angle of screw dipole; the blunt crack in inhomogeneity can evidently strengthen the repulsion of hard matrix to dislocation and weaken the attraction of soft matrix to dislocation; there is an unstable equilibrium position for screw dipole when the inhomogeneity is hard and the equilibrium position will approach to the interface as the curvature of blunt crack increasing; the variation of will appear a critical value that can change the direction of stress intensity factor.