超弹性NiTi合金循环相变诱发塑性本构模型∗

摘要

为定量描述镍钛形状记忆合金循环相变诱发塑性导致的超弹性退化行为，在广义粘塑性框架下对Graesser模型进行了拓展，考虑了奥氏体和马氏体弹性模量的差异以及马氏体非线性硬化行为，引入循环相变过程中相变应力和残余应变的演化方程，建立了超弹性NiTi合金循环相变诱发塑性本构模型，总结了模型参数确定方法。通过镍钛形状记忆合金微管的循环相变试验结果和模拟结果的对比表明，提出的模型能够很好地预测镍钛形状记忆合金的循环相变诱发塑性行为。%To describe quantitative super-elasticity degradation behavior caused by the cyclic transformation in-duced plasticity of NiTi shape memory alloy,the Graesser model was extended in the frame of general visco-plasticity to consider the difference between austenite and martensite elastic moduli and the nonlinear hardening behavior of martensite.The evolution equations of transformation stress and transformation strain during cyclic transformation were introduced in the proposed model to capture the behavior of the cyclic transformation in-duced plasticity and the method of parameter calibration was provided.The comparison of experimental and simulated results of NiTi micro-tube subj ected to cyclic loading show that the proposed model can predict rea-sonably the cyclic transformation induced plasticity of NiTi shape memory alloy.