Mountain Highway For Liang Qiaozhi Magnetorheological Dampers Control Study

Prestressed reinforced concrete (PC) continuous beam bridge is a common type in expressway in the mountain area. As the transport junction and crucial engineering between the mountain area and the outside, its aseismatic capability attracts the engineers' attention all the time. The disastrous consequences of Wen Chuan earthquakes on 5.12 showed that the aseismatic capability of expressway bridge in mountain area affects whether the rescue work in the disaster area can carry out smoothly and whether the reconstruction can proceed successfully after earthquake, the importance is self-evident. Based on the case of a PC continuous beam bridge, Qi Fang Bridge, this paper analyzed the seismic response control on the bridge structure lengthways and compared the efforts of various algorithms, and etc, including mainly the follows:1. This paper summarized the status quo of vibration control at home and abroad, introduced detailedly its development history, basic notions, the ways of researching and applying in the structure vibration control, especially in bridge engineering. The superiority of the control performance of intelligent Magnetorheological(MR) damper was expounded by means of comparing the merits and demerits of various methods in vibration control.2. In order to simulate the damping effect more accurately and conveniently in bridges with MR dampers, the mechanical model must be sought or established, which can reflect the strongly non-liner characteristic better. After generalized the predecessors' study on the mechanical property and mechanical model of MR damper based on the experiments, introduced a set of representative models such as Bingham model, revised Bingham model, Bouc-Wen model and phenomenon model and simulated the Bingham model in SIMULINK, the basis of the reasonable selection of MR damper model is provided.3. As to the earthquake responses of the long span continuous beam bridges, the classic motion equation based on the identical ground motion, cannot be applied any more. This paper establishes and deduces the motion equation of the semi-active control system, which is subjected to seismic multi-support import, and deduces the state equation of the control system by introducing the state vector. At the same time, it discusses about the selection of mass matrix, damping matrix, stiffness matrix, the input of the seismic waves and introduces the optimal control algorithm method for the active structural control and of semi-active control of MR dampers, laying the theoretical foundation for the future study.4. By investigating control effort of the intelligent MR damper of the expressway bridge seismic response, comparing the damping control effort of uncontrolled strategy with the efforts of passive-off and passive-on control strategies, semi-active control and active control of intelligent MR damper, then analyzing them, we can obtain the characteristics and its superiority of semi-active control of the intelligent MR damper.