GCr15凹模环形裂纹电磁热局部跨越止裂的模拟研究  

Numerical Simulation to Round Crack Prevention by Electromagnetic Heating Bridging Over in GCr15 Dic

作　　者：付宇明[1] 

机构地区：[1]燕山大学,秦皇岛066004

出　　处：《应用力学学报》2005年第1期99-102,共4页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(50275128);河北省自然科学基金资助项目(599255)

摘　　要：裂纹止裂技术是当前工业生产和实际应用中急需解决的关键问题;利用电磁热效应对带有裂纹的金属构件进行止裂,是达到延长工作寿命、提高安全性可靠性的一种行之有效的方法;本文采用有限元方法研究了带有半埋藏环形裂纹的轴对称GCr15凹模电磁热局部跨越止裂;建立了超强脉冲电流放电瞬间,环形裂纹尖端附近电场、温度场和热应力场的耦合关系。数值模拟分成热-电耦合(焦耳热问题)和热-机械耦合两个过程来实现,通过数值解析轴对称模型,给出了脉冲放电瞬间GCr15凹模中的电流-温度-热应力的求解过程,得到了脉冲放电瞬间半埋藏环形裂纹局部跨越止裂时凹模的温度场和热应力场。数值模拟研究结果表明:由于热集中效应,在放电瞬间裂纹尖端金属熔化,并形成局部堆焊,阻止了干线裂纹源的开裂,达到了止裂的目的。The technique of crack prevention is necessary for current industrial production. To prevent cracks in a metal component from propagating, the electromagnetic heat effect can be adopted as an effective way to extend service life and improve security and reliability. The crack prevention by bridging over is investigated in metal die GCr15 with half embedding round crack finite element method. The evolutive process of the coupled current temperature stress fields is simulated numerically, the thermal stress around crack is solved at the moment while the pulse current is switched on. Numerical simulation shows that small welded joints can be formed a small sphere near the crack tip to prevent the main crack from extension.

关 键 词：半埋藏裂纹 跨越止裂 脉冲放电 温度场 热应力场 

分 类 号：O482.6[理学—固体物理] O346.1[理学—物理]