引入超导带材堆叠块体的混合眼型高温超导磁体的力学特性分析

Mechanical analysis of trapped field HTS-stacked ring magnets with and without HTS stack inserts

高温超导磁体具有零电阻特性,通过适当的磁化过程,就可以在没有外部电源的情况下保持强磁场.使用商用高温超导带制造的眼型高温超导磁体已经证明了其具有稳定的强磁场捕获能力,并且相对于传统超导块材,其尺寸更加灵活.然而,在场冷磁化过程中,由洛伦兹力引起应力应变可能会对磁体造成损伤.因此,在本论文的研究中,建立并验证了三维数值计算模型,以研究混合眼型高温超导磁体中的应力和应变.计算了场冷磁化下磁体的应力分布,并讨论了样品的固定方法对应力集中和应变的影响.研究还发现,增强中心捕获磁场的高温超导带材堆叠块体在磁化过程中受到不平衡的洛伦兹力,这是由于眼型磁体的不对称捕获磁场而导致的,此不平衡力产生在高温超导堆叠中的不对称应力分布.这些发现为眼型高温超导磁体的机械行为提供了重要的见解,可以指导其设计的优化,以适应各种应用,如核磁共振、磁悬浮和高温超导电机等.

Trapped field high-temperature superconducting(HTS)magnets have zero resistance and can maintain strong magnetic fields without external power supplies once properly magnetized.HTS-stacked ring magnets fabricated with commercial HTS tapes have demonstrated the ability to trap large and stable fields with more flexible sizes.However,during field cooling(FC)magnetization,the Lorentz forces and corresponding mechanical stress may cause damage to the magnets.Therefore,in this study,3D numerical models are established and verified to investigate the stress and strain in HTS-stacked ring magnets.The stress distribution in the HTS-stacked rings under FC magnetization is calculated and the influence of sample fixation methods on the stress concentration and strain is discussed.The study also reveals that HTS stack inserts,which enhance the central trapped field,are subjected to unbalanced Lorentz force during magnetization,causing asymmetric stress distribution in the HTS stacks due to the asymmetric trapped field of the HTS-stacked ring magnets.These findings offer important insights into the mechanical behaviour of HTS-stacked ring magnets,which can guide the optimization of their design for various applications,such as nuclear magnetic resonance,Maglev,and HTS machines.