载流薄板中裂纹形成瞬间尖端附近的应力场

利用电磁场的热效应对带有裂纹的载流导体进行裂纹止裂，是为了达到延长其工作寿命，提高安全性、可靠性的一种行之有效的方法。本文在文献1]的基础上，以导电弹性体的麦克斯威尔方程为出发点，借助于边界条件和初始条件，推得了载流无限大薄板在形成裂纹的瞬间，裂纹尖端附近电流密度、温度和应力的具体表达式。通过算例分析证实了：在给定参数的情况下，通入适当强度的电流时，在电流所产生的焦耳热源的作用下，裂尖区域处的温度将瞬时升高，同时伴有压应力的产生，从而可达到阻止裂纹扩展的目的。

Stress Field near Instantaneous Deformed Crack Tip in Conducting Plate

When magneto-elasticity and thermoelasticity have been formed and well developed, to stop the propagation of internal crack in a current conductor by electromagnetic heat effect becomes an effective way for reaching the goal of crack arresting. Based on the thesis1], and Maxwell's equations for an elastic body and taken into account of the boundary and initial conditions, the equations for the determination of electrical current density near a crack tip in conducting infinite thin plate have been obtained. All the equations are concerned at the moment while the crack is deformed instantly. According to these equations, the temperature and stress expressions at the crack tip were obtained. The calculated examples show that attributing to the Joule heat source provided by electric current, the temperature around crack tip grows up instantly and the compressive stresses appear too, if the parameters have been set up previously and a current with proper intensity has been switched on. So the spreading of the crack could be prevented.