超弹性NiTi合金丝动力特性试验及本构模型研究  

DYNAMICAL BEHAVIOR AND CONSTITUTIVE MODEL OF SUPERELASTICITY NITI SHAPE MEMORY ALLOY WIRE:EXPERIMENT AND THEORY

作　　者：钱辉[1,2] 李宏男[2] 宋钢兵[3] 陈淮[1] 

机构地区：[1]郑州大学土木工程学院,郑州450001 [2]大连理工大学建设工程学部,大连116024 [3]美国休斯敦大学机械工程系,休斯敦77204

出　　处：《固体力学学报》2011年第4期353-359,共7页Chinese Journal of Solid Mechanics

基　　金：国家"十一五"科技支撑计划重大项目(2006BAJ03A03)和重点项目(2006BAJ06B03);中国博士后科学研究基金面上项目(20100471004);教育部高等学校博士学科点专项科研基金(20104101120009);大连理工大学海岸和近海工程国家重点实验室研究基金(LP1017);河南省教育厅自然科学计划项目(2010B560016)资助

摘　　要：形状记忆合金(SMA)是一种兼具感知和驱动功能的功能材料,因其独特的形状记忆效应、超弹性和高阻尼等特性,成为土木工程结构振动控制的理想材料.论文研究了超弹性NiTi丝的动力特性和应变率相关的本构模型.试验测试了NiTi丝在不同应变率下的力学性能,建立了应力增量与应变率的关系方程.在试验的基础上,提出了改进的SMA本构模型,新模型能够描述SMA应变率相关特性,并通过仿真结果和试验结果的比较,验证模型的正确性和适用性.研究结果表明:动力荷载下,NiTi丝每循环耗散能量、割线刚度和等效阻尼比在开始阶段均快速增大,当应变速率大于1.0×10-3/s后,趋于平缓;数值结果和试验结果吻合较好,改进模型在一定程度上可以描述NiTi丝应变率相关的动力特性.Shape memory alloys （SMA） are a class of novel functional materials used as both actuators and sensors. Due to unique thermomechanical behaviors such as shape memory effect （SME）, superelasticity and high damping property, et al, they are perfect candidates for structural vibration control in civil engi- neering. This paper presents a study of the dynamic behavior and strain-rate-dependent constitutive model of superelastic NiTi SMA wires. Cyclic tensile tests on NiTi SMA wires at different stain rates were carried out to assess their dynamic properties. The equations that were used to describe the relationship between the stress increments and the strain rates were proposed. Base on the experimental data,an improved SMA constitutive model that can capture the strain-rate-dependent property was presented. To certify the validity and suitability of the improved SMA model,the comparisons between the numerical results and experimental data were made. The results show that the mechanical behaviors of NiTi SMA wires,including energy dissipation per cycle,secant stiffness and equivalent damping rate,initially increase with the increase of strain rate,then tend to stability once strain rate is greater than 1.0×10^-3/s, showing good agreement with the experimental data. Therefore,to a certain extent, the improved model can be used to describe the strain rate dependent property of NiTi SMA wires.

关 键 词：形状记忆合金 本构模型 动力特性 拉伸试验 

分 类 号：TG139.6[一般工业技术—材料科学与工程]