螺型位错偶极子与界面刚性线的弹性干涉

ELASTIC INTERACTION OF A SCREW DISLOCATION DIPOLE WITH AN INTERFACIAL RIGID LINE

研究了晶体材料中螺型位错偶极子和界面刚性线夹杂的弹性干涉作用。利用复变函数方法,得到了该问题的复势函数以及应力场的封闭形式解答。求出了作用在螺型位错偶极子中心的像力和力偶矩,并分析了界面刚性线几何条件和不同材料特征组合对位错偶极子平衡位置的影响规律。研究结果表明:当位错偶极子不断靠近刚性线时,刚性线对螺型位错偶极子的运动有很强的排斥作用。当刚性线的长度和材料剪切模量比达到临界值时,可以改变偶极子和界面之间的干涉机理。同时,偶极子偶臂的方向对其自身的平衡也有很大的影响。

The problem of the elastic interaction between a screw dislocation dipole and an interracial rigid line was investigated. By using the complex variable method, the closed form solutions of complex potentials and the stress fields produced by the screw dislocation dipole are obtained when the dipole is located in one media. The image force and the image torque acting on the screw dislocation dipole center are also calculated. The equilibrium position of the screw dislocation dipole is examined for various material property combinations and interfacial rigid line geometries. The results show that the interfacial rigid line always repels the screw dislocation dipole when the dipole approaches the interface. If the length of the rigid line or the ratio of two shear moduli reaches a critical value, the presence of the rigid line can change the interaction mechanism between the dipole and the interface. In addition, the influence of the dipole arm orientation on the equilibrium of the dipole is considerable.