基于滚轴支座基础智能隔震结构的非光滑主动控制

Nonsmooth active control method for base-smart isolated structures with roller bearings

  • 摘要: 以滚轴支座基础隔震结构作为受控结构研究对象, 在该隔震结构的隔震层施加主动控制装置, 形成智能隔震体系, 以控制隔震层的位移, 提高结构的安全性. 在智能隔震结构中引入非光滑控制算法, 基于隔震层位移和速度反馈, 提出了智能隔震结构的非光滑控制算法, 进一步根据Lyapunov稳定理论, 推导了在非光滑控制下智能控制闭环系统的全局有限时间稳定性. 结合一栋六层滚轴支座基础隔震结构, 进行了非光滑主动控制算法下和LQG主动控制算法下的地震响应控制仿真分析. 结果表明, 智能隔震结构可有效控制结构的位移, 与被动隔震结构相比较上部结构的地震响应有一定程度的减小, 同时提出的非光滑控制算法与LQG控制算法相比较具有更好的控制效果, 相比LQG控制算法通过较少的反馈量即可实现反馈控制, 且非光滑控制算法具有良好的稳定性.

     

    Abstract: In applied structural control technology, base-isolated technology has become popular due to its advantage of simple shock absorption, stable performance, and reasonable cost. Currently, base isolation is extensively applied worldwide, and its role in mitigating the seismic response of structures continues to grow. Moreover, it has been proven effective in decreasing seismic response of structures under recent strong earthquakes. However, the displacement at the isolation layer is sometimes large under strong earthquakes, which will decrease the safety of the structure and perhaps lead to the failure of the isolation layer. Therefore, in this study, the base-isolated structure with roller bearings is taken to investigate the seismic response control of structures, and the active control devices are added in the isolation layer of the isolated structure to decrease the seismic displacement at the isolation layer, so that a smart-isolated structure is formed. Nonsmooth control algorithm is introduced in the smart-isolated structure. Based on the feedback of the velocity and displacement of the isolation layer, nonsmooth control algorithm is proposed for designing the smart-isolated structure. Moreover, according to Lyapunov stable theory, the global finite time stability of intelligent control closed-loop system under nonsmooth control is deduced. A six-layer isolated structure with roller bearings is used as an example, and a simulation analysis of seismic response control is performed based on the nonsmooth active control algorithm and linear quadratic Gaussian (LQG) active control algorithm. The results show that the smart-isolated technology can effectively control seismic displacement at the isolation layer, and compared with the passive isolated technology, the superstructure seismic response is significantly decreased. Meanwhile, the results demonstrate that compared with the LQG control algorithm, the nonsmooth control algorithm has a better control effect and can implement feedback control for base-isolated structures by using fewer feedbacks. Furthermore, the nonsmooth control algorithm has great stability.

     

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