NiTi形状记忆合金丝的约束回复应力输出特性及本构模型  

Constrained Recovery Stress Output Characteristics and Construction of Constitutive Model of NiTi Shape Memory Alloy Wire

作　　者：刘博 王社良[1] 何露 李昊 杨涛 李彬彬[1,3] LIU Bo;WANG Sheliang;HE Lu;LI Hao;YANG Tao;LI Binbin(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;School of Urban Planning and Municipal Engineering,Xi’an Polytechnic University,Xi’an 710048,China;Key Laboratory of Structural Engineering and Earthquake Resistance,Ministry of Education,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]西安工程大学城市规划与市政工程学院,西安710048 [3]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》2020年第10期10082-10087,共6页Materials Reports

基　　金：国家自然科学基金(51678480);陕西省自然科学基础研究计划(2019JQ-578);陕西省教育厅项目(18JK0332);陕西省教育厅重点实验室科学研究计划项目(17JS071);陕西省科技统筹创新工程重点实验室项目(2014SZS04-P04)。

摘　　要：为促进工程结构领域对形状记忆合金(SMA)这一智能驱动材料的应用,研究了预应变大小和热循环次数对Ti-50.8(质量分数,%)Ni SMA丝的约束回复应力-温度曲线、最大约束回复应力、逆相变特征温度、相变温度区间和相变滞后温度区间等约束回复应力输出特性的影响,并在试验数据集合的基础上建立以温度和完全热循环次数为输入、约束回复应力为输出的BP神经网络(即按照误差逆向传播训练的神经网络算法)迟滞模型。结果表明:最大约束回复应力和马氏体逆向变特征温度随预应变的增加而增加;6%预应变的NiTi SMA丝在第一次热循环中约束回复应力最大,逆向变特征温度值最高。经过五次热循环后,NiTi SMA丝的约束回复应力-温度曲线逐渐稳定。该神经网络迟滞模型的数值计算结果与试验数据较为吻合,平均绝对误差不超过5%,且简单实用、精确度高,具有一定的工程指导意义。In order to promote the application of the shape memory alloy(SMA)as an intelligent driving material in the field of engineering structure,the effect of pre-strain and thermal cycle times on the constrained recovery stress-temperature curve,maximum constrained recovery stress,inverse phase transition characteristic temperature,phase transition temperature range and phase transition hysteresis temperature range of Ti-50.8wt%Ni SMA wires were studied.Based on the experimental data set,the hysteresis model of BP neural network(neural network algorithm trained according to error reverse propagation)with temperature and complete thermal cycle times as input and constrained recovery stress as output was established.The results show that the maximum constrained recovery stress and the characteristic temperature of martensite reverse transformation increase with the increase of pre-strain.In the first thermal cycle,NiTi SMA wire with 6%pre-strain exhibits the highest constrained recovery stress and the highest characteristic temperature of reverse variation.After five times of thermal cycle,the recovery stress-temperature curve of NiTi SMA wire gradually reached stability.The numerical results of neural network hysteresis model are in good agreement with the experimental data,and the mean absolute error of the calculated results is less than 5%.The hysteresis model of BP network is simple,pratical and accurate,and has certain engineering guiding significance.

关 键 词：形状记忆合金 形状记忆效应 约束回复应力 相变特征温度 相变滞后 BP神经网络 

分 类 号：TG139.6[一般工业技术—材料科学与工程]