考虑裂纹对感应电流影响的高温超导体多裂纹问题研究

The high temperature superconducting (HTS) materials quickly developed into one of the most promising advanced materials since they were found because of their characteristics of high critical temperature and high critical current density. However, the fracture phenomena frequently occurred in high temperature superconducting structures when they are applied in the low temperature environment and the strong electromagnetic field bring grim challenges for the safety and effectiveness of HTS in their applications. And these phenomena also make the fracture analysis of HTS become an important foundation in the safety and functional designs of HTS. Therefore, the multiple crack problems of HTS subjected to extreme conditions are considered in this program, and a theoretical model of induced current disturbed by the multiple cracks will be established to describe the influence of multiple cracks on the trapped flux which has been observed in many experiments. Based on the disturbance model, the numerical calculations and the experimental research methods will be adopted to analyze the multi-field coupled and nonlinear behaviors of mechanics in HTS with multiple cracks. According to these researches of the foundational problems, the numerical iterative analysis mode of the flux distribution and the fracture failure analysis mode under extreme conditions in HTS with multiple cracks will be established, which will provide an effective research approach for the multiple crack problems and lay a solid foundation for revealing the mechanisms and laws of fracture, and then provide a theoretical basis and technical support to promote the development of HTS in engineering applications.

高温超导材料自被发现以来就因其高临界转变温度、高临界电流密度等特性而迅速发展成为最具应用前景的先进材料之一。但在低温环境及强电磁场作用下高温超导结构中时常发生的破裂现象为其在应用中的安全性与有效性带来了严峻挑战，这也使得断裂特性分析成为高温超导结构安全性设计与功能性设计中的重要基础性环节。本项目针对极端条件下高温超导体的多裂纹问题，通过建立多裂纹对超导体内感应电流的绕动模型来描述很多实验中已观测到的裂纹对超导体俘获磁通的影响，并在此理论模型基础上结合数值计算与实验研究方法来分析含多裂纹高温超导体的多场耦合非线性力学行为。通过对这些基础性问题的研究，建立起含有多裂纹的高温超导体在磁化过程中磁场分布的数值迭代分析模式及其在极端条件下的断裂失效分析模式，从而为高温超导体的多裂纹问题研究提供有效途径并为揭示其断裂破碎机制与规律打下坚实的基础，进而为推动高温超导材料应用的发展提供理论依据和技术支持。

低温环境及强电磁场作用下的断裂特性分析是高温超导结构安全性设计与功能性设计中的重要基础性环节。本项目针对极端条件下高温超导体的多裂纹问题，通过建立多裂纹对超导体内感应电流的绕动模型来描述很多实验中已观测到的裂纹对超导体俘获磁通的影响，并在此理论模型基础上结合数值计算与实验研究方法来分析含多裂纹高温超导体的多场耦合非线性力学行为。通过对这些基础性问题的研究，建立起含有多裂纹的高温超导体在磁化过程中磁场分布的数值迭代分析模式及其在极端条件下的断裂失效分析模式，从而为高温超导体的多裂纹问题研究提供有效途径并为揭示其断裂破碎机制与规律打下了坚实的基础。