7×19构型NiTi形状记忆合金绞线超弹性试验研究  

Experimental Investigation on Superelastic Behaviors ofNiTi Shape Memory Alloy Cables with 7×19 Sections

作　　者：周玉浩 连鸣[1,2] 王颜凯 苏明周[1,2] ZHOU Yuhao;LIAN Ming;WANG Yankai;SU Mingzhou(School of Civil Engineering,Xi an University of Architecture and Technology,Xi an 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Xi an University of Architecture and Technology,Xi an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]西安建筑科技大学结构工程与抗震教育部重点实验室,西安710055

出　　处：《材料导报》2024年第21期238-247,共10页Materials Reports

基　　金：国家自然科学基金(52078411;52478205);陕西省创新能力支撑计划-青年科技新星项目(2022KJXX-47);陕西省教育厅青年创新团队科研计划项目(22JP041)。

摘　　要：为充分发挥大直径NiTi形状记忆合金(SMA)绞线的超弹性性能,在常温下对单丝直径1.0 mm的7×19构型SMA绞线进行了循环拉伸试验;分析了热处理方案、应变幅值、循环次数、预训练和加载速率等因素对其超弹性的影响,得到了各因素下SMA绞线的残余应变、能量耗散、等效粘滞阻尼比、强度和刚度等力学参数变化规律。结果表明:针对本研究的7×19构型SMA绞线,400℃退火10 min的热处理方案下其相变应力和恢复率最高,热处理时间过长会造成这些特性严重退化;SMA绞线内部单丝变形和应力发展不均匀程度更高,滞回曲线无明显相变平台;恒定幅值拉伸下SMA绞线的初始弹性模量和极限应力变化相对较小,而相变平台高度、恢复率以及等效粘滞阻尼比退化较为明显;通过预训练的方式可以减轻SMA绞线的功能损伤,显著减小残余变形,提高可恢复能力;加载速率对SMA绞线的马氏体应力和屈服平台切线模量的影响较大,当加载速率超过1×10^(-2) s^(-1)后,滞回曲线对加载速率的变化不再敏感。试验结果可为7×19构型SMA绞线的应用提供数据支持。This study aimed to investigate the cyclic tensile behavior of 7×19 NiTi shape memory alloy(SMA)cables with a single wire diameter of 1.0 mm,in order to optimize their superelastic properties for engineering applications.A comprehensive analysis was conducted to assess the effects of various factors,including heat treatment strategy,strain amplitude,number of cycles,pre-training,and loading rate on the mechanical parameters of SMA cables.The obtained mechanical parameters,such as residual strain,energy dissipation,equivalent viscous damping ratio,strength,and stiffness were examined under different conditions.The results showed that the annealing temperature of 400℃for 10 minutes produced the highest phase transformation stress and recovery rate for the 7×19 SMA cable configuration,which deteriorated with prolonged annealing time.The deformation and stress development of the single wire inside the SMA cable are more uneven,and the hysteresis curve has no obvious phase transformation platform.The initial elastic modulus and ultimate stress of SMA cables under constant amplitude tension are relatively small,while the degradation of phase transition platform height,recovery rate and equivalent viscous damping ratio is obvious.Moreover,the pre-training method can reduce the functional damage of the SMA cables,significantly reduce the residual deformation,and improve the recovery ability.The loading rate has a great influence on the martensitic stress and the tangent modulus of the yield platform of the SMA cables.When the loading rate exceeds 1×10^(-2) s^(-1),the hysteresis curve is not sensitive to the change of the loading rate.The results provide experimental data support for the application of 7×19 section SMA cables.

关 键 词：7×19构型形状记忆合金绞线 超弹性 热处理 力学性能 循环加载 

分 类 号：TG139.6[一般工业技术—材料科学与工程]