Nb_(3)Sn高场复合超导体临界性能力学变形效应的多尺度模拟  

MULTISCALE SIMULATION OF MECHANICAL DEFORMATION EFFECTS ON CRITICAL PROPERTIES OF Nb_(3)Sn HIGH FIELD COMPOSITE SUPERCONDUCTORS

作　　者：杨绪佳 何宇新 张鑫 杨小敏 王涛 乔力 Yang Xujia;He Yuxin;Zhang Xin;Yang Xiaomin;Wang Tao;Qiao Li(Institute of Applied Mechanics,College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学机械与运载工程学院应用力学研究所,太原030024

出　　处：《力学学报》2022年第3期719-731,共13页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金资助项目(11772212)。

摘　　要：A15型Nb_(3)Sn超导体是制造高场(>10 T)超导磁体线圈的主要材料,被广泛应用于磁约束可控核聚变、高能物理等强磁场超导磁体装备制造领域.力学变形诱导的Nb_(3)Sn超导临界性能退化给高场超导磁体装备的电磁性能指标和安全稳定运行造成了极其不利的影响.鉴于Nb_(3)Sn超导体具有复杂的多尺度结构特征,不同尺度下变形与超导电性能耦合行为是相互关联的,本文建立了考虑微/细/宏观关联的非线性力电磁耦合本构模型,提出了从原子尺度A15晶体结构到超导体微结构到宏观非均质Nb_(3)Sn复合超导体的多尺度模拟模型.基于多晶体有限元方法,对静水压加载条件下Nb_(3)Sn多晶体超导临界温度衰退和单轴拉压加载条件下Nb_(3)Sn复合多晶体临界性能衰退行为进行了模拟预测,预测结果与实验观测结果定性吻合.该模型揭示了Nb_(3)Sn复合超导体变形-超导电性能多尺度耦合机理,实现对高场超导体力、电、磁、热耦合行为的预测,有助于提高对A15型金属间化合物高场超导复合材料力、电、磁、热多尺度耦合行为的认识和描述能力,为强磁场超导磁体的设计与制造提供有力的理论支撑.A15 superconducting Nb_(3)Sn has shown great promise for applications in the international thermonuclear experimental reactor,and high energy physics.In these high field applications,the stress/strain arises from the cool-down and operation process of the superconducting magnet,inducing the performance degradation of the Nb_(3)Sn cable-inconduit conductors,which is a critical issue in the superconductivity applications and developments.Due to the complex multi-scale structure of Nb_(3)Sn composite,the electromechanical coupling responses at different scales are intrinsically interrelated.On the basis of the micro-meso-macro frame analysis,this paper intends to study the effects of strain induced variations of the characteristic parameters of material microstructure on the superconducting properties of Nb_(3)Sn and establish the constitutive model which accounts for the multiscale coupling in strained Nb_(3)Sn.A framework for micro-tomacro transitions for multi-scale analysis of multifilamentary superconducting composites is developed.Using this model,we respectively predict the critical properties degradation responses of Nb_(3)Sn polycrystal under hydrostatic pressure and Nb_(3)Sn composite under axial loading,the predicted results are in qualitative agreement with the experimental observations..This study reveals the multiscale coupling mechanism of electromechanical effects in Nb_(3)Sn high-field superconducting composite.With the aid of the study,the multiscale features in electromechanical coupling behavior in Nb based A15-type compounds are identified.The study will promote the material engineering application process,and the results of which are promising to engineer optimized large-scale superconducting high magnetic field systems.It is helpful to improve the understanding and description of the strain sensitivity of Nb_(3)Sn,and to provide a solid theoretical support for the manufacture of high-field superconducting magnets.The developed simulation model provides a basis for the detailed description of

关 键 词：应变效应 多尺度耦合特性 力电磁耦合 多晶体有限元 

分 类 号：TB331[一般工业技术—材料科学与工程]