通电瞬时板内半无限长裂纹尖端域的应力场

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，推得了在向含半无限长直线裂纹的无限大导电薄板内通入电流的瞬时，裂纹尖端附近电流密度的表达式。在此基础上，得到了裂纹尖端区域处温度和应力的具体表达式。算例表明，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，并伴有压应力的产生，从而可达到阻止裂纹扩展的目的。

THE STRESS FIELD NEAR THE CRACK TIP OF A SEMI-INFINITE CRACK INSIDE A CURRENT- CARRYING PLATE AT THE MOMENT WHILE THE CURRENT IS SWITCHING ON

With the Maxwell's equations for an elastic body and the boundary and initial conditions, the equations for determination of electrical current density near a crack tip are obtained. The tip of the semi-infinite crack is located inside an infinite thin current-carrying plate. All the equations hold at the moment while the current is switching on. From these equations the temperature and stress expressions at the crack tip are obtained too. The numerical examples show that under the Joule heat source provided by electric current, the temperature around crack tip grows up instantly and the compressive stresses appear too. Consequently, propagation of the crack could be arrested.