NiTi形状记忆合金回复力-温度模型改进与实验研究

摘要: 针对NiTi形状记忆合金的马氏体不完全逆转变现象带来的回复力模型预测误差，开展了NiTi形状记忆合金一维回复应力-温度模型研究。在Brinson的形状记忆合金(SMA)一维本构模型基础上，增加马氏体回复因子为内变量，给出了马氏体回复因子与预应变的关系，综合考虑温度和应力对马氏体体积分数的影响，构造NiTi形状记忆合金回复应力-温度改进模型，通过实验测试了不同预应变量的NiTi合金回复应力与温度关系曲线。研究表明：本文提出的改进模型预测的NiTi形状记忆合金回复应力-温度曲线，与实验结果曲线吻合较好，本研究结果对于提高NiTi形状记忆合金回复力预测精度具有重要意义。

Improved and Experimental Research on the Recovery Stress Model of NiTi Shape Memory Alloys

Abstract:To eliminate the prediction errors of the recovery stress model of NiTi SMAs caused by the incomplete reverse martensitic transformation, an improved prediction model of recovery stress had been developed based on the one-dimensional Constitutive Behavior model proposed by Brinson for shape memory alloys (SMAs). This model regarded the martensitic recovery factor as an internal variable and took the stress and temperature into account as influencing factors to martensitic content of SMAs. The curve of recovery stress of NiTi SMAs with different initial strains versus temperature was measured by experiment. Compared with the experimental results, the computation result showed that the model had a certain accuracy to calculate the recovery stress-temperature curve.