形状记忆合金电阻-应变模型

Electrical Resistance-Strain Model for Shape Memory Alloys

目的利用热动力学电阻理论和拉伸试验,建立超弹性状态的形状记忆合金(SMA)电阻-应变模型.方法在SMA热动力学电阻模型的基础上,采用数值分析和实验验证相结合的方法,创建了SMA超弹性分段线性化模型.在完成SMA单向拉伸试验的基础上,提取具有代表性的实验数据,验证电阻-应变模型的有效性.结果得到电阻-应变试验曲线,并建立了曲线的数学表达式.结论所提出的SMA电阻-应变模型与实验结果吻合很好,可以有效地表达SMA超弹性电阻-应变之间的关系.

The paper focuses on the establishment of strain for shape memory alloy （SMA） wires. Based constitutive model of the electrical resistance （ER） and on the thelmo-mechanical theory of SMAs, an experiment of ER for the austenite SMA wires was carried out in the laboratory and a constitutive model for the ER performance was developed based on the experimental data and numerical simulation. The developed model can be represented by a three stage curve which includes two linear stages and a parabolic one. The simplified model can be effectively used in structural health monitoring which used SMA wire as sensors by embedding it in the structure.