一种对公路桥梁振动半主动控制的新策略

为了有效抑制隔震桥梁震后过大的梁体及支座位移,提出了一种适合MRD的基于力反馈(FF)形式的半主动控制策略.首先提出了采用隔震装置提供的恢复力作为主要反馈信号的半主动控制策略,然后给出了欲使MRD产出预期阻尼力而应施加的电流准则,最后设计出基于力反馈形式的半主动闭环控制系统.分别采用Passive-off,Passive-on,FF和CO等四种控制算法对一座三跨隔震连续梁桥的各评价指标进行了计算.结果表明:FF算法对梁体位移、支座位移和墩底剪力的控制效果要比其他三种算法显著.

A New Semi-active Control Strategy of Highway Bridge Vibration

To effectively suppress the oversize displacement of both grider and bearing on seismically isolated bridges after an earthquake， a new semi-active control strategy based on the force-feedback (FF) fit for magneto rheological dampers (MRD) was proposed. First， the semi-active control strategy taking the restoring force provided by seismic isolation devices as the main feedback signal was proposed. Then， the current criteria which were applied to help the damping force produced by MRD approximate to the desired control force were proposed. Finally， the semi-active closed-loop control system based on the force-feedback was designed. The various evaluation criteria of tri-span seimicically isolated continuous grider bridges with Passive-off control， Passive-on control， FF control and clipped optimal (CO) control were computed respectively. The results indicated that the control effects on girder displacement， bearing displacement and base shear under the FF control are more significant than those of Passive-on control， Passive-off control and CO control.