SMA压电复合减震装置电力学性能及其本构模型

针对形状记忆合金(shape memory alloy,简称SMA)阻尼器控制力不可调和压电摩擦阻尼器启动难的问题,提出了一种SMA单元和压电摩擦单元依次工作的复合减震装置,进行了相应的电力学性能试验,分析了位移幅值、激励频率和输入电压对复合减震装置力学性能的影响。在试验结果的基础上,建立了以速率符号、电压和位移为神经元输入的优化反向传播(back propagation,简称BP)神经网络预测模型。结果表明,该复合减震装置的滞回曲线饱满且基本对称,工作性能稳定,随着电压的增大,滞回环的面积逐渐增大,耗能能力不断增强。在位移幅值为12mm、电压为120V下,单圈耗能量提高了138.23%,等效阻尼比提高了94.23%。两种智能材料经过合理组合而成的SMA压电复合减震装置耗能好、适应性强,可以更好地用于工程结构的减震控制。BP网络预测模型能够较好地跟踪SMA类复合减震装置的输出,而优化后的BP网络更加稳定,能够快速得到误差更小的网络模型,该神经网络算法为SMA类复合减震装置本构模型的建立和应用提供了新途径。

Electrodynamic Performance and Its Constitutive Model for SMA Piezoelectric Composite Control Device

To solve the problem that the control force of shape memory alloy (SMA) damper is not adjustable and piezoelectric friction damper is difficult to start up, a novel composite control device whose SMA unit and piezoelectric friction unit work in turn is proposed; and the corresponding electrodynamic property test is carried out. On the basis of the experiment data, BP neural network model for control device is established which takes the sign of velocity, voltage and displacement as input neurons. Results show that the hysteresis curve of the composite control device is full and basically symmetric; and the work performance is stable. As the voltage increases, the area of the hysteresis loop increases gradually, and the energy dissipation capacity increases. At the displacement amplitude of 12mm, the lap energy dissipation in 120V voltage increases by 138.23%, and the equivalent damping ratio increases by 94.23%. The damping device achieved by the combination of two intelligent materials has good energy-dissipating capacity and strong adaptability, and it can be better used for damping control of engineering structures. BP network prediction model can well track the output of the SMA composite control device, and the optimized BP network is more stable and can more quickly get error smaller network model; the neural network algorithm provides a new way for the establishment and application of constitutive model of SMA composite damping device.