Nb_(3)Sn超导复合股线非线性力学行为研究  

Nonlinear static and dynamic mechanical behaviors of Nb_(3)Sn superconducting composite wire:experiment and analysis

作　　者：姜浪 张兴义 周又和 Lang Jiang;Xingyi Zhang;You-He Zhou(Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China,Lanzhou University,Lanzhou,730000,China;Department of Mechanics and Engineering Sciences,College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,730000,China)

机构地区：[1]Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China,Lanzhou University,Lanzhou,730000,China [2]Department of Mechanics and Engineering Sciences,College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,730000,China

出　　处：《Acta Mechanica Sinica》2023年第3期42-55,共14页力学学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.11872196,12232005 and U2241267).

摘　　要：本文通过对Nb_(3)Sn超导复合股线在77 K和300 K下进行准静态加卸载拉伸和疲劳实验,研究了Nb_(3)Sn超导复合股线的非线性力学行为,结果表明:Nb_(3)Sn超导复合股线的准静态应力-应变曲线和能量耗散具有很强的非线性.同时,考虑塑性应变产生的损伤退化,推导了卸载过程中非线性和线性卸载模量,提出了考虑损伤的双曲面弹塑性本构模型来预测准静态加卸载应力-应变响应和能量耗散;通过疲劳损伤演化模型分析和预测Nb_(3)Sn超导复合股线在77 K和300 K下疲劳过程中的能量耗散.理论与实验结果对比表明:准静态加卸载拉伸实验中损伤退化是能量损耗产生非线性的主要原因.此外,对Nb_(3)Sn超导复合股线的疲劳断裂模式进行了分析,结果表明:Nb 3Sn芯丝组在77 K时表现为脆性断裂,在300 K时表现为韧性断裂.这些新发现为研究Nb_(3)Sn超导复合股线的非线性力学行为提供了新的视角.In this paper,the nonlinear mechanical behaviors of Nb_(3)Sn superconducting composite wires have been investigated by the quasi-static loading-unloading tensile and fatigue tests at the temperature of 77 and 300 K,respectively,which indicates that the quasi-static stress-strain curves and energy dissipations exhibit strong nonlinearity.Meanwhile,the nonlinear and linear unloading modulus are derived by considering the damage degradation,and the elastic-plastic constitutive is proposed to predict the quasi-static loading-unloading stress-strain responses and energy dissipation.Moreover,the damage evolution model has been conducted to elucidate the energy dissipation of fatigue tests for the Nb_(3)Sn composite wire at the temperature of 77 and 300 K.The combination of experimental and theoretical results indicates that the nonlinearity of energy dissipation is caused by damage degradation during quasi-static loading and unloading tensile tests.Furthermore,the fatigue fracture modes of Nb_(3)Sn composite wires also have been analyzed,which indicated that the Nb_(3)Sn sub-elements show brittle fracture at the temperature of 77 K while ductile fracture at the temperature of 300 K.These findings provide novel insights into the nonlinear mechanical behaviors of Nb_(3)Sn superconducting composite wires.

关 键 词：NONLINEARITY Elastic-plastic constitutive Energy dissipation Damage degradation Nb_(3)Sn composite wires 

分 类 号：TB33[一般工业技术—材料科学与工程]