形状记忆合金伪弹性行为模拟  

Simulation of pseudo-elasticity behaviors of shape memory alloy

作　　者：张振华[1] 绳飘[1] 王钦亭[1] 王磊[1] 

机构地区：[1]河南理工大学土木工程学院,焦作454000

出　　处：《应用力学学报》2016年第5期820-825,936,共6页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(51308195;11172198);河南省科技厅科技攻关项目(132102210252);河南理工大学博士基金(B2013-066)

摘　　要：基于对伪弹性形状记忆合金(SMA)典型应力-应变曲线的特征分析,在原Graesser本构模型中增加简洁多项式来描述SMA应力诱发马氏体相变完成后在变形马氏体相下继续加载阶段的变形特征;并引入应变幅值与混相下SMA弹性模量的关系来改进不同应变幅值下卸载时SMA的应力-应变关系,从而提出了一种新的SMA一维本构关系模拟其伪弹性力学行为。该模型对直径为0.5mm的NiTi合金丝的拉伸加载、卸载试验曲线的模拟结果表明:改进本构模型与原Graesser模型相比,其能够准确地模拟SMA在不同应变幅值下加载和卸载应力-应变关系。此外,通过研究SMA本构模型的物理关系,推导出了控制SMA滞回曲线特征的关键参数fT与相变临界应力、弹性常数之间的明确关系,可利用该关系直接确定参数fT,摆脱了只靠试算获取该参数的传统做法,其准确性得到了试验验证。Based on the characteristic analysis for typical stress-strain curves of pseudo-elasticity shape memory alloy(SMA), a new constitutive model is proposed to simulate the pseudo-elasticity behaviors of SMA. The concise polynomials are added based on Graesser model to describe the loading process of the deformed martensite after SMA stress-induced martensitic transformation finishing at loading process in the new model, while the relationship between the stress amplitude and elastic modulus at mixed phase state is introduced to fit the stress-strain relationship at unloading process. The results of the tensile tests of Ni Ti SMA fitted by the improved model show that the new model fits accurately the SMA stress-strain curves under loading and unloading process in different strain amplitude through comparing with Graesser model. Moreover, a formula of the key parameter fT which controls the hysteretic characteristics of SMA curves on material constants of SMA is derived by investigating the physical meaning of the improved constitutive model of SMA, then the parameter fT can be conveniently determined by the formula and its accuracy is verified.

关 键 词：形状记忆合金 伪弹性 本构模型 

分 类 号：O344.1[理学—固体力学] TB381[理学—力学]