【摘要】 用复变函数方法研究了带有中间穿透裂纹的载流薄板在瞬间电流通入时,在裂纹尖端处由于电流集中及电磁热效应而形成的点热源的计算方法,进而推导并计算了由此热源在裂纹前缘产生的温度场和应力场。通过控制通入电流密度,可以使裂纹尖端温升达到熔化状态,至使裂尖钝化,由温升产生的压应力可以遏制裂纹的扩展。在文中讨论了裂尖附近材料的热传导系数、线胀系数、弹性模量随温度的变化,及其对应力场的影响。更多还原

【Abstract】 In this paper, a thin current-carrying plate with a penetrated crack is analysed when an instant electric current is switched on. Complex analysis method is used to propose the way of how to calculate the point heat source which is formed owing to the heat concentration effect on the crack tip. Furthermore, the temperature field and the stress field near the crack leading edge are also deduced. Theoretical analysis and experimental surreys show that if the electric current density is controlled, the material around the crack tip will melt due to the heat concentration effect, at the same time the super passive tissue and the compressive stress around the crack tip can prevent the crack from propagating. The influence of heat transfer coefficient varying with tempera- ture on stress field is also discussed.更多还原