【摘要】 在地震作用下,高架桥由于其结构特点会产生大幅地震振动,而半主动控制能够有效地控制结构的大幅地震振动.半主动控制一般以被动控制为主体,仅需少量能量用以改变被动控制系统的参数或切换工作状态,以适应系统对最优状态的跟踪.半主动控制往往是针对既有工程结构,所以只能在控制装置和算法上进行改进以达到对既有工程结构的最优控制.为了充分发挥半主动控制的能力,可以考虑从结构设计上进一步提高半主动控制效果.根据高架桥的结构特点,建立了高架桥-MR阻尼器体系的简化模型.在EL-Centro、Taft和Kobe地震波作用下,使用MR阻尼器中修正的宾汉姆模型和剪切型最优控制(Clipped-optimal control)算法对高架桥的半主动地震响应控制进行了研究,分析了结构参数对基于MR阻尼器半主动控制效果的影响.更多还原

【Abstract】 The characteristics of elevated highway bridges render them selves susceptible to earthquakes.Hence,the semi-active control is usually taken into consideration due to its high level of vibration mitigation.It is known that semi-active control is based upon passive control and only requires lesser energy for adjusting the parameters of passive control system or transferring current working state to track the control system at the optimal state.Semi-active control is generally aimed at the existing engineering structures,thus requiring selecting appropriate control device and corresponding strategy to achieve the optimum control.It is worth pointing out that the performance of semi-active control can be further enhanced by resorting to ameliorating the structural design.According to the characteristics of elevated highway bridges,a simplified model for elevated highway bridges-Magneto-rheological(MR)dampers is developed in this paper.The modified Bingham model for MR dampers and the clipped-optimal control strategy are selected to constitute MR damper based semi-active control for elevated highway bridges under earthquakes.Then,the effects of structure parameters of elevated highway bridges are investigated on MR damper based semi-active control using the EL-Centro,Taft,and Kobe waves.更多还原