超导线圈绕制过程的力学行为研究

Mechanical stress in superconducting coils during winding process

为了增加超导线圈中导线的占空比,提高超导磁体正常运行时的机械稳定性,通常在超导线圈绕制过程中施加一定的绕制张紧力.绕制张紧力的大小会对超导磁体的失超特性和退化性能产生重要的影响,因此有必要对绕制过程中的机械应力进行详细的分析.本文仔细地分析了绕制过程中导线的受力情况,进行了一些合理的假设和近似,提出了研究超导线圈绕制应力的理论模型,并根据轴对称结构的弹性力学方程式推导了计算超导线圈应力应变分布的理论公式.基于该模型分别研究了单一绕组的超导线圈和双绕组的超导线圈的绕制应力,分析了绕制张紧力和绕组的各向异性特性对径向应力和环向应力的影响.在该理论模型分析结果的基础上可以进一步分析多物理场作用下的超导磁体的应力应变行为,为高性能超导线圈的设计和建造提供理论指导.

In order to increase the filling factor of conductor in superconducting coils and improve the mechanical stability of superconduct- ing magnet, the pre-tension is always applied to the conductor during winding the coils. Because the winding pre-tension has a great effect on the quench and degradation performance of superconducting magnet, it is necessary to analyze the mechanical stress caused by the fabrication. First, the winding physical process of conductor is analyzed. Then the theoretical model is developed to calculate the winding stress of superconducting coils based on some reasonable assumptions and approximations. And some formulas used for stress and strain are derived from the theory of elastic mechanics. Two kinds of superconducting coils （one consists of one type of wire, and the other one consists of two types of wires.） are researched according to the model. The effects of winding pre-stress and material anisotropy on radial stress and hoop stress in superconducting coils are also analyzed. On the basis of the analyzed results, one can further research the stress and strain of superconducting coils under the effect of multiphysics and give some theoretical suggestions for the design and construction of superconducting coils.