超弹性形状记忆合金棒的力学性能试验

MECHANICAL PERFORMANCE TESTS OF SUPERELASTIC SHAPE MEMORY ALLOY BARS

将超弹性形状记忆合金(Shape Memory Alloy,简称SMA)圆截面棒材原料加工得到标准试件。针对上述SMA棒试件进行了拟静力试验,系统研究了应变幅值、加卸载速率、循环加卸载次数对其相变应力、等效刚度、单位循环耗能量、等效阻尼比和残余应变五个力学性能参数的影响。试验研究表明,SMA棒可提供较为理想的超弹性效应。同时,由试验结果亦可观察到SMA棒的耗能和阻尼能力较低。总的来看,超弹性SMA棒可提供较大的输出力和稳定的复位性能,适合作为大尺寸阻尼器的复位器件用于工程结构的减振控制。

Raw shape memory alloy （SMA） bars are manufactured into standard test specimens. The pseudo static tests are performed to obtain the stress-strain curves of such SMA bars. The effects of strain amplitude, loading rate and cyclic number on performance parameters of the SMA in bar forms, such as equivalent stiffness, energy dissipation per cycle, equivalent damping ratio and residual strain, are examined. The experimental results show that the SMA bars can display typical superelastic effects. Meatnime, generally low engergy dissipation and damping of SMA bars can be observed. In summary, the superelastic SMA bars can provide large output force and stable re-centering property. Therefore, SMAs with larger sections show potential for using as the recentering components of passive dampers for vibration control of engineering structures.