基于形状记忆合金的TMD半主动控制

TMD semi-active control with shape memory alloy

针对建筑结构在随机荷载或风荷载作用下可能发生的频率不确定问题,特别是结构自振频率会随振幅的大小而发生漂移的非线性振动问题,提出性能可靠、构造简单的形状记忆合金SMA-TMD自适应半主动控制系统.从理论上探讨形状记忆合金在变刚度TMD控制装置中的应用,并进行相应的参数设计.同时,在研究随机荷载作用下TMD系统动力特性的基础上,结合短时傅里叶变换(STFT)设计出该系统的自适应半主动控制算法.算例表明,SMA-TMD自适应控制系统能较好地识别结构系统的时频特性,并进行有效的控制,具有性能可靠和自适应能力强等特点.该自适应控制系统较传统的TMD被动控制减震效果更好,鲁棒性更强.

In view of the uncertain frequency of building structure vibration caused by random excitation or wind load, a SMA -TMD semi-active adaptive control system with reliable performance and simple structure is presented in this paper. The application of shape memory alloy in the variable stiffness TMD control equipment is investigated theoretically, and corresponding parameters are designed. Based on the study of dynamic characteristics of TMD system, the SMA - TMD adaptive control algorithm is designed by dint of short time Fourier transform. Simulation study indicates that the SMA-TMD system is effective and self-adaptive in identifying the time-frequency characteristic of the structure, and it is more robust and effective in reducing the vibration response compared with traditional TMD control.