Wang Longfei, Feng Peihua, Wu Ying, Liu Zishun
State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, Shaanxi Engineering Laboratory for Vibration Control of Aerospace Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel). 2020 Jul 13;13(14):3116. doi: 10.3390/ma13143116.
Tensile-compressive asymmetry and the ratcheting effect are two significant characteristics of shape memory alloys (SMAs) during uniaxial cyclic tests, thus having received substantial attention in research. In this study, by redefining the internal variables in SMAs by considering the cyclic accumulation of residual martensite, we propose a constitutive model for SMAs to simultaneously reflect tensile-compressive asymmetry and the cyclic ratcheting effect under multiple cyclic tests. This constitutive model is temperature dependent and can be used to reasonably capture the typical features of SMAs during tensile-compressive cyclic tests, which include the pseudo-elasticity at higher temperatures as well as the shape-memory effect at lower temperatures. Moreover, the proposed model can predict the cyclic mechanical behavior of SMAs subjected to applied stresses with different peak and valley values under tension and compression. Agreement between the predictions obtained from the proposed model and the published experimental data is observed, which confirms that the proposed novel constitutive model of SMAs is feasible.
拉压不对称性和棘轮效应是形状记忆合金（SMA）在单轴循环试验中的两个重要特性，因此在研究中受到了广泛关注。在本研究中，通过考虑残余马氏体的循环累积来重新定义形状记忆合金中的内部变量，我们提出了一种形状记忆合金的本构模型，以同时反映多循环试验下的拉压不对称性和循环棘轮效应。该本构模型与温度有关，可用于合理捕捉形状记忆合金在拉压循环试验中的典型特征，包括较高温度下的伪弹性以及较低温度下的形状记忆效应。此外，所提出的模型可以预测形状记忆合金在拉压作用下承受不同峰值和谷值的外加应力时的循环力学行为。观察到所提出模型的预测结果与已发表的实验数据之间的一致性，这证实了所提出的新型形状记忆合金本构模型是可行的。
