Mechanism of thermo-mechanical coupling failure and on-line monitoring technology for high-temperature superconducting cable joints
高温超导电缆接头热-力耦合失效机理与在线监测技术

摘要

高温超导电缆接头在运行过程中同时承受电流热效应与机械应力作用，其热-力耦合失效已成为制约工程化应用的重要因素。研究基于热传导与力学响应的耦合机理分析，揭示了接头内部温升分布、应力集中及材料性能退化之间的相互作用规律，明确了界面接触、电流均匀性和冷却条件对失效过程的影响。针对高温超导接头在复杂工况下的安全隐患，提出了结合光纤传感、红外成像与电磁信号分析的在线监测技术方案，实现温度场与应力场的实时采集与状态评估。通过建立多物理场数值模型与实验验证平台，形成了一套可用于预测失效风险、优化接头结构及运行维护策略的技术体系，为高温超导输电工程的可靠运行提供理论支持与工程参考。

Abstract

High-temperature superconducting cable joints are subject to both current thermal effects and mechanical stresses during operation, and their thermo-mechanical coupling failure has become a key factor restricting engineering applications. Based on the analysis of the coupling mechanism between heat conduction and mechanical response, this study reveals the interaction laws among internal temperature rise distribution, stress concentration, and material performance degradation of the joints, and clarifies the influence of interface contact, current uniformity, and cooling conditions on the failure process. Aiming at the potential safety hazards of high-temperature superconducting joints under complex working conditions, an on-line monitoring technology scheme combining optical fiber sensing, infrared imaging, and electromagnetic signal analysis is proposed to realize real-time acquisition and state evaluation of temperature fields and stress fields. By establishing a multi-physics numerical model and an experimental verification platform, a technical system that can be used to predict failure risks, optimize joint structures, and formulate operation and maintenance strategies is formed, providing theoretical support and engineering references for the reliable operation of high-temperature superconducting power transmission projects.