压电材料中螺型位错与含界面刚性线圆形涂层夹杂的干涉

INTERACTION BETWEEN A SCREW DISLOCATION AND A CIRCULAR COATED INCLUSION WITH AN INTERFACIAL RIGID LINE IN PIEZOELECTRIC MATERIALS

研究了压电材料中位于基体的螺型位错与含界面刚性线圆形涂层夹杂的电弹耦合干涉问题。运用复变函数方法,获得了基体、涂层和夹杂中复势函数的精确级数形式解答。基于广义Peach-Koehler公式,计算了作用在位错上的像力。讨论了刚性线几何条件、界面层厚度和材料电弹特性对位错力和位错平衡位置的影响规律。结果表明:对于软夹杂和软涂层的情况,刚性线长度存在一个临界值改变像力的方向。螺型位错先被吸引后被排斥,在夹杂附近有一个稳定的平衡点。对于硬夹杂和硬涂层的情况,位错一直被排斥,刚性线对位错力的影响较小。

The problem of the electroelastic coupling interaction between a screw dislocation and a circular coated inclusion with an interfacial rigid line in piezoelectric solids is investigated. Utilizing the complex variable method, the explicit series form solutions of the complex potentials in the matrix, the coating layer and the inclusion regions are derived. Based on the obtained complex potentials, the image force on the screw dislocation is then calculated by using the generalized Peach-Koehler formula. The image force and the equilibrium position of the dislocation are discussed in detail for various rigid line geometries, coating layer thicknesses and piezoelectric material property combinations. The main results show that, when the length of the rigid line reaches a critical value, the original direction of the image force may be changed for the case of the soft inclusion and coating layer. The screw dislocation is attracted first then repelled by the inclusion and the rigid line leading to a stable equilibrium position when the dislocation approaches the coated inclusion from infinity. For the case of the stiff inclusion and coating layer, the dislocation is always repelled by the inclusion and the impact of the rigid line on image force is a little.