高速公路跨线桥地震反应的智能磁流变控制

Smart control of seismic response of expressway overcrossing using magnetorheological damper

探讨了高速公路跨线桥智能磁流变控制的效果,并与主动控制、磁流变(MR)阻尼器的passive- off控制及passive-on控制时的减震控制效果进行了系统的比较分析。研究中MR阻尼器的半主动控制算法选用限幅最优控制算法,其主控制器采用H_2/LQG方法来设计,并基于原系统的降阶模型来设计MR阻尼器的最优控制力。仿真分析结果表明,采用MR阻尼器对高速公路跨线桥进行控制,可以有效地减小结构的动力反应,明显改善其抗震安全性。MR阻尼器在passive-off控制及passive-on控制时等效为被动摩擦阻尼器,其控制效果与适用范围均有限;MR阻尼器的半主动控制力可以出色地追踪主动控制力时程,其控制效果与主动控制时非常接近,因此可以作为主动控制的替代方案。

This paper investigates the control performance of semiactive magnetorheological（MR） damper employed in expressway overcrossing, which is systematically compared with active, passive-on and passive-off control strategies. The clipped-optimal control algorithm is chosen for the semiactive control of MR damper and, an HJLQG control algorithm is selected for the design of primary controller to determine the ideal force of MR dampers. Rusuhs of simulation show that the MR damper is capable of significantly reducing the dynamic responses of expressway overcrossing and can greatly improve its safety under earthquakes. The passive-on and passive-off modes of MR damper can be taken as passive friction dampers, whose control performance is very limited, and cannot hold effect for a set of earthquakes. The semiactive control force of MR damper can trace the active control force very well and achieve a similar level of performance to the active controller. Thus MR damper can be taken as a good alternate to the active control strategy.