电磁热效应裂纹止裂中绕流屏蔽效应的数值模拟

Numerical simulation on the current flowing over and shielding IN crack PREVENTION using electro-magnetic heat effect

  • 摘要: 本文采用数值模拟方法研究了电磁热效应多裂纹止裂中的绕流屏蔽问题,在数值模拟中应用了热-电耦合(焦耳热问题)的分析方法.计算结果表明:由于裂纹的存在导致电流热集中效应,使裂尖处金属熔化形成焊口,遏制了裂纹的扩展;在多裂纹导体中通入相同电流时,多裂纹间的绕流屏蔽效应并不十分明显,裂尖的温度和温度梯度主要取决于裂纹的长度;随着裂纹长度的变化,裂纹尖端的温度场和温度梯度场均有很大的变化,本文给出了它们的定量分析结果.

     

    Abstract: The current flowing over and shielding in crack prevention using electro-magnetic heat effect is studied with numerical simulation method. In the analysis, the thermal-electrical coupling theory is applied. The numerical calculation shows that owing to the existing of crack, the current concentration is so remarkable that the crack tip is melted and a welded joint is formed. Consequently, crack propogation is prevented. When the same current is acted in the conductor with more than one cracks, the current flowing over and shielding effect is not remarkable, and the temperature and the temperature gradient at crack tip are mainly affected by the length dimension of cracks. With the change of the crack length, the temperature and the temperature gradient at the crack tip change markedly. The results of quantitative analysis of temperature and the temperature gradient are given in the paper.

     

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