具有半边裂纹导电薄板放电瞬间的温度场数值模拟

采用数值模拟方法 ,模拟计算了具有半边裂纹的导电薄板在放电瞬间的温度场分布。计算结果表明 :在裂纹尖端附近由于电磁热的集中效应 ,可使材料熔化形成焊口 ,裂纹尖端处的曲率半径显著增大 ,并且焊口的温度分布与形状是不完全对称的。裂纹尖端焊口形状的模拟计算结果与试验结果非常吻合。从温度梯度的分布结果可知 ,裂纹前缘附近在放电过程中将产生很大的压应力 ,可显著减少甚至是消除裂纹前缘处的扩展应力数值 ,抑制了裂纹主干线的形成 ,可达到遏制裂纹扩展的目的

Numerical simulation of temperature field of plate with a semi edge crack at current switching moment

A numerical simulation is proposed for simulating the temperature field of plate with a semi edge crack at current switching moment. The calculation result shows that the crack tip is melted and the welded joint is formed as the results of electro magnetic heat concentration effect. The curvature of the ends of crack is increased remarkably. The temperature distribution and form is incompleteness symmetry. The shape of welded joint by the numerical simulation has an agreement with the experimental results. From the results of temperature gradient distribution, it is shown that the compressive stresses appear and spreading stresses decrease remarkably near the ends of the crack during the current switching process. Therefore, the formation and growth of the main crack is prevented.