大跨度拱桥磁流变阻尼器减震控制

MR DAMPER SEMI-ACTIVE CONTROL TO SEISMIC RESPONSE OF ARCH BRIDGE

对拱桥这种大型结构在地震激励作用下实施减震控制是提高结构安全性的重要途径。为实现磁流变阻尼器在拱桥振动控制中的应用,提出在拱桥上设置磁流变阻尼器的减震控制方案。以改进的现象模型作为磁流变阻尼器的计算模型,采用LQG控制器一基于Sign函数的半主动控制算法,建立拱桥结构-磁流变阻尼器控制系统。最后,建立一平面拱桥模型,对该拱桥采用磁流变阻尼器进行减震控制分析。仿真分析结果表明通过合理地设计控制策略,拱桥磁流变阻尼嚣半主动控制可使拱桥地震反应取得良好的减震效果,而且半主动控制效果明显优于被动控制。

Two schemes of control to reduce seismec responses of arch bridges with Magneto-Rheological dampers (MRD) are presented. In the semi-active control system of arch bridge-MRD, modified phenomenological model (Yang, 2001 ) is selected as the mechanical model of MRD, and Linear Quadratic Gaussian (LQG)-based Sign function control algorithm is used to command the action of MRD. An arch bridge model is used as a simulation example to verify the proposed control scheme. Numerical results show that the performance of the proposed semi-active control strategy is superior to that of passive control of MRD, and the displacement responses of the bridge are effectively decreased and internal forces are reduced to a certain extent in the semi-active control scheme.