含埋藏椭圆形裂纹金属构件电磁热止裂时热应力场分析

对带有椭圆埋藏裂纹金属构件在脉冲放电瞬间的热应力场进行了理论分析。在热应力场的求解中，利用了热传导和非定常热应力理论，由求解的热应力场公式发现：在脉冲放电瞬间，电磁热在裂纹尖端形成热压应力场，热压力场可有效地抑制裂纹的扩展。以Cr12MoV模具钢中埋藏椭圆裂纹止裂为例，具体计算了脉冲放电瞬间的热应力场分布情况，为空间裂纹电磁热止裂技术的实际应用提供了理论基础。

ANALYSIS ON THERMAL STRESS FIELD AT THE MOMENT OF CRACK ARREST BY ELECTROMAGNETIC HEATING IN METAL COMPONENT WITH ELLIPTICAL EMBEDDING CRACK

Theoretical analysis is made on the thermal stress field at the time of pulse current discharge in a metal structure with an elliptical embedding crack. In finding the thermal stress field, theories of heat conduction and unsteady thermal stress are used. It can be found from the formula for solving the thermal stress field that thermal stress field of the crack tip at time of pulse current discharge is formed, and thermal pressure field can effectively inhibit the crack propagation. And taking an example of Cr12MoV die steel with elliptical embedding crack, distribution of thermal stress field at time of pulse current discharge is calculated. The study provides a theoretic basis to the applications of stopping spatial crack with electromagnetic heating.