Study on Performance Degradation of Multi-Layer Spiral Superconducting Cable Under Bending Load

Spiral superconducting cable based on 2G HTS (high temperature superconductivity) technique is potential in high field superconducting magnet application, due to excellent mechanical and electromagnetic performance. During manufacturing process into superconducting magnet, multiple layer spiral cable is wound under complex forces, then leading to critical current degradation. Mechanical simulation is beneficial to clarify the influence of bending behavior on cables’ critical current. In this paper a new mechanical analysis finite element model of multi-layer spiral superconducting cable is constructed. Cables are bent to a circular mold with transvers force. In terms of mechanical response, it is different from the commonly used "2-points bending mode" that applies bending moment at two ends of the cable. Comparable experiments are conducted as validation. The critical current of the cable is measured after bending by four-probe method at 77 K. The experimental results show good agreement with the mold bending simulation while 2-points bending method overestimates the critical current of cables. In this paper, a new simulation method for the bending process of spiral cable to magnets is proposed, which can more accurately predict the critical current degradation caused by mechanical failure under lateral forces.