Experiment and modeling analysis are performed to study the evolution dynamics due to thermomechanical coupling in cyclic phase transformation responses of a superelastic NiTi shape memory alloy rod under periodic stressing. Synchronized acquisition of time evolutions in temperature and stress-strain curve of the rod were realized in the frequency range of 0.0004 ∼ 4Hz (average stress rate from 0.42MPa/s to 4200MPa/s). Significant frequency dependent oscillations, drifts and stabilizations in the strain, temperature and stress-strain curves are quantified and the roles of thermomechanical coupling in the observed evolution dynamics of the responses are revealed. It is found that the stress-strain responses are non-isothermal over the tested frequency range and that the evolution dynamics is quite distinct from that of displacement-controlled cyclic phase transition (Yin et al., JMPS, 2014) due to the non-prescribed heat sources and the implicit nature of the response. The evolution dynamics are modelled by two coupled non-linear governing equations to obtain numerical and approximate analytical expressions of the transient and steady-state stress-strain and temperature oscillations. It is shown that, for given material and ambient properties, the thermomechanical responses under cyclic-stressing can be divided into three regions and are essentially governed by the non-dimensional time scale $\overline{t_p}$and stress $\Delta \overline{\sigma }$.

进行了实验和建模分析，研究了在周期性应力作用下超弹性NiTi形状记忆合金棒的循环相变响应中热机械耦合引起的演化动力学。在0.0004〜4Hz（平均应力率从0.42MPa / s到4200MPa / s）的频率范围内，实现了棒的温度和应力-应变曲线的时间演变的同步采集。量化了应变，温度和应力-应变曲线中依赖于频率的明显振荡，漂移和稳定性，并揭示了热机械耦合在观察到的响应演化动力学中的作用。（Yin et al。，JMPS，2014）归因于非规定的热源和响应的隐性。通过两个耦合的非线性控制方程对演化动力学进行建模，以获得瞬态和稳态应力应变和温度振荡的数值和近似解析表达式。结果表明，对于给定的材料和环境特性，循环应力下的热机械响应可以分为三个区域，并且基本上由无量纲的时间尺度控制。$\overline{{Ť}_p}$和压力 $\Delta \overline{\sigma }$。