高温超导电机磁体支撑结构焊接残余应力分析及影响研究!

焊接残余应力不仅可能使高温超导电机磁体支撑结构产生裂纹,还可能与外加载荷叠加后改变磁体支撑结构的承载能力。应用轴对称模型及单元生死技术,对高温超导电机磁体支撑结构进行了焊接数值模拟,得到了焊缝残余应力的分布规律,同时在结构强度分析中考虑了焊接残余应力的影响。数值模拟结果表明:最大残余Mises应力出现在焊缝区域,远离焊缝区的应力几乎为零;整体退火对焊接残余Mises应力的降低非常有效;焊接残余应力和外载荷作用下的Mises应力进行了叠加,导致磁体支撑结构的强度明显下降。研究结果为磁体支撑结构的设计、生产工艺的优化及降低焊接残余应力提供了理论依据。

Welding Residual Stress Analysisand Influence Research of Magnet Supporting Structure Used in HTS Motor

The effect of welding residual stress not only induces the cracks of structure,but also could change the loading capacity when consider external load and welding residual stress.Using axisymmetric model and live-dead element technology,this study aims to investigate the distributions of welding residual stress and strength verification with welding residual stress in a magnet supporting structure used in HTS motor rotor.The results indicate that the highest residual stress exist in the welding region,and the other region is nearly zero;heat treatment can reduce the residual stress;the cumulative effect by residual stress and external load descend the strength of the magnet supporting structure obviously.These results are attractive for the design,technologic optimization,and welding residual stress control of the magnet supporting structure used in HTS motor.