摘要
Graesser模型以应力-应变增率形式表述了形状记忆合金(SMA)本构关系,具有形式简单、能反映SMA动态力学特性的优点;但忽略了加载路径对模型参数的影响,造成预测误差．依据超弹性SMA的拉伸试验结果,在Graesser模型基础上提出了改进模型:将滞回曲线分为加荷阶段、卸荷至马氏体逆相变完成阶段、母相弹性卸荷阶段三部分,每部分采用各自的参数．数值模拟比较表明:改进模型能很好地捕捉超弹性SMA在静荷下的应力-应变特征,在一定程度上反映加荷速率对其滞回性的影响,且较Graesser模型具有更高的预测精度．
The Graesser's model described the constitutive relation of superelastic shape memory alloy (SMA) in the form of stress-strain s differential coefficient. It had the relative simple formulation, and could reflect SMA s dynamic mechanical properties, but it ignored the effects of loading path on the model parameters, which produced difference. According to one-dimensional cyclic loading tests of superelastic shape memory alloy wires, an improved model was put forward on the basis of the Graesser's model. The improved model divided the full loop into three parts: the loading branch, the unloading branch before the completion of the reverse transformation and the elastic unloading branch of austenite, each part adopted its respective parameters. Numerical simulations were conducted. Comparisons indicate that the improved model accurately reflects the quasi-static hysteresis characteristics of SMA, and can reflect the effects of the loading rate on the superelastic behavior of SMA to some extent. Compared with the Graesser's model, the improved model has more prediction accuracy.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2006年第z1期157-161,共5页
Journal of Dalian University of Technology
基金
国家杰出青年科学基金资助项目(50025823)
海外青年学者研究基金资助项目(50328807).
