高架桥梁地震响应磁流变阻尼器(MR)半主动控制

Magneto-rheological(MR) dampers semi-active control of earthquake response for elevated bridge

通过比较被动、主动控制方法的控制效果,研究了磁流变(Magneto-Rheological)阻尼器半主动控制方法在高架桥梁抗震控制中的作用。根据高架桥梁的结构特点,将典型的墩-支座-桥面结构简化为一个两自由度的线性系统,依据3个设计目标:最小化支座响应、最小化桥墩响应及最小化两者响应,分别用高阻尼的橡胶支座进行被动控制、用二次线性调节器(LQR)方法进行主动控制、以MR阻尼器为半主动控制设备,用二次线性调节剪切最优控制器(LQR-Clipped)控制方法进行半主动控制。分别使用上述3种控制方法对同一个系统,在EI-Centro、Gebze、Maxico3种地震激励下进行数值计算。数值结果表明,在最小化支座响应及最小化两者响应控制目标时,MR半主动控制与主动控制具有相同的控制效果,但在最小化支座响应时,桥墩的响应很大;然而,最小化两者响应时,支座及桥墩均有很好的控制效果。

The semiactive control efficiency of MR dampers was obtained with comparing the passive and active control strategies. According to the structural characteristics of the elevated bridge,a twodegreefreedom model was provided from the typical pierbearingdeck structure.Three control goals,minimizing the pier response,minimizing the bearing response and minimizing both responses,were used.The passive control was assumed to have a highdamping rubber bearing, and linear quadratic regular(LQR) was used for the active control system.LQRClipped optimal control strategy was used to command MR damper in semiactive control.The control effectiveness of different control strategies were compared subjected to three kinds of earthquake excitation about different control goals.The results demonstrated that the MR semiactive control can research the active control performance if the control goal is to reduce the bearing response and the both responses,but will increase the pier response for minimizing the bearing response goal.However both the active and semiactive control strategies showed excellent performance for the pier response and the bearing response.