大尺寸超弹性镍钛形状记忆合金螺旋弹簧滞回性能

Hysteretic Performance of Large Scale Superelastic NiTi Shape Memory Alloy Helical Spring

利用2种镍钛形状记忆合金(SMA)研制了大尺寸超弹性螺旋弹簧,对其进行了单轴反复荷载作用下的滞回性能试验,研究了超弹性SMA螺旋弹簧的恢复力特性与耗能能力,分析了加载频率、位移幅值对2种SMA螺旋弹簧滞回曲线以及等效刚度、单位循环耗能、等效阻尼比和残余位移等力学性能参数的影响;采用刚弹性模型和Bouc-Wen模型,建立了适用于整体结构分析的SMA螺旋弹簧简化恢复力模型,并利用该模型进行了数值模拟。结果表明:超弹性SMA螺旋弹簧具有稳定的滞回曲线,且具有良好的复位性能和大变形能力,可用于结构自复位控制装置的研发;数值模拟结果与试验结果吻合较好,验证了简化恢复力模型的正确性。

The large scale superelastic helical springs were fabricated with two types of NiTi shape memory alloy （SMA）, and hysteretic performance test of superelastic SMA helical springs was carried out under uniaxial cyclic loading. The restoring force behavior and energy dissipation capacity of SMA helical springs were studied, and the influences of loading frequency, displacement amplitude on the hysteretic curves and the mechanical behavior parameters, such as equivalent stiffness, energy dissipation per cycle, equivalent damping ratio and residual displacement, were analyzed. Combining the rigid-elastic model and the Bouc-Wen model, a simplified restoring force model of SMA helical spring was established, which was available to integral structure, and the numerical simulation was performed with the model. The results show that SMA helical springs exhibit stable hysteresis curves, excellent re-centering performance and large deformation capacity. The remarkable properties make the SMA spring an ideal subcomponent foruse in re-centering devices. The numerical results match closely with the experimental data, proving the validity of the proposed restoring force model of the SMA helical springs.