高温超导复合线材的多场耦合多尺度力电行为及细观机制研究

高温超导复合线材是绕制超导磁体的基本结构，也是新一代热核聚变装置磁体系统的备选线材。其在实际工况下的力、热、电、磁、输运性能不仅是超导磁体设计的基础，也是其安全运行和可靠性评估的前提。系统的研究其在制备和应用过程中的力-热-电-磁耦合行为，探讨这些耦合行为与其细观结构和特征之间的关联，是优化其加工工艺，提升其力、电、超导性能的关键环节。所涉及的具有随机、多场耦合、强非线性特征问题的理论建模和定量分析也是目前力学学科的前沿课题。基于此本项目拟展开对高温超导线材：微结构演化和力、热、电有效性能的表征；超导性能的应变敏感特征及微结构依赖的输运理论；以及高温超导电缆多层级力-电行为建模等方面的研究。通过这些研究以期建立和完善高温超导线材及结构力电行为分析的多场耦合多尺度理论框架和有效定量分析程序，为我国高温超导线材的制备工艺水平的提升、超导电缆、线圈和磁体系统的优化设计和安全运行提供理论参考。

The high-temperature superconducting（HTS） wire (i.e., Bi2212 ) is not only the basic structure for fabricating of superconducting magnets, but also the candidate wire for the new generation of the thermo-nuclear fusion reactor, as DEMO or CFERT (Chinese Fusion Engineering Test Reactor) . The mechanical, thermal and electromagnetic behaviors of the wires in operating conditions are the key issues both in the optimized design and in the safe operation and evaluation of superconducting magnets. It is necessarily vital for improving the process technique and the current transport capability to study systemically the mechanical-thermal-electric coupling behaviors and reveal the relation between the coupling behaviors and the micro-structures of HTS wires. The involved theoretical modeling and quantitative analysis on this kind of multi-scale interaction, multi-field coupling and multi-fold nonlinearity problem have become an important topic or hotspot in the present mechanics area. Based on these considerations, some researches will be conducted in this project, such as: the evolution of the micro-structure and the characterization of the effective mechanical, thermal and electric properties of wires, the strain-sensitive superconducting performance and the micro-structure dependent transport theory of the wire; the multi-stage mechanical modeling of HTS cables and some basic experiments on the mechanical properties of wires, etc. After that, A multi-fold coupling, multi-scale theoretical frame of the electromagnetic behaviors of high-temperature superconducting materials and structure will be built, and the effective quantitative analysis approach and code will be developed. All these will provide a theoretical support for promotion of the manufacture process, the current transport capability of HTS wires and the optimized design or safe operation of the HTS cables，coils and magnets.