超弹性NiTi形状记忆合金棒力学性能研究
Research on Mechanical Performance of Superelastic NiTi Shape ？？Memory Alloy Bars

研制了具有2种化学成分的超弹性NiTi形状记忆合金(NiTi SMA)圆截面棒材，并对其进行了力学性能试验研究，分析了应变幅值、加载速率对2种SMA棒的应力？灿Ρ淝？线以及等效刚度、单位循环耗能、等效阻尼比和残余应变等力学性能参数的影响。通过有限元软件对SMA棒的力学性能进行了数值模拟，并对比了有限元模拟结果与试验结果。结果表明：超弹性SMA棒可提供较大的输出力和良好的复位性能，适合作为复位部件及辅助耗能部件用于工程结构的减振控制；数值模拟结果和试验结果吻合较好，采用有限元方法可较为准确地模拟超弹性SMA棒的力学性能。
NiTi superelastic shape memory alloy (SMA) circular section bars with two types of chemical compositions were developed, and the mechanical performance tests were carried out. The influences of strain amplitude, loading rate on the stress？？strain curve and the performance parameters such as equivalent stiffness, energy dissipation per cycle, equivalent damping ratio and residual strain of the two SMA bars were analyzed. The mechanical performance of SMA bars was simulated by finite element software, and the simulated results were compared with the test results. The results indicate that the developed superelastic SMA bars are suitable for the re？？centring and supplementary energy dissipation components in seismic control due to their large output force and excellent superelastic effect. The numerical results agree well with the test results, and the finite element method can accurately simulate the mechanical performance of SMA bars