Study On Control Of Reducing Ceismic Response For Cable-stayed Bridge Based On Mode Analysis

The cable-stayed bridge is a new type of structures with long-spans and flexibility. The bridges are much attractive to domestic and oversea scholars, engineers and technicians because of their low cost, appealing aesthetics and their overcrossing ability. Much attention has been paid to this kind of bridges for structural analysis and seismic design. On the other hand, achievements have been obtained in building structural control in recent years. But up to now researches are as open ended as possible for reducing seismic response of long-span bridge with structural active control techniques. So, the research is carried out for active control of reducing seismic response of cable-stayed bridge based on the mode analysis.The research work mainly focuses on the following aspects:The analysis model of reducing seismic response for cable-stayed bridge is established in Chapter 2. Two samples of cable-stayed bridge without structural control are also analyzed for dynamic performances and seismic responses. The modified mode combination method is used in the analysis of seismic response.The algorithm of the linear quadratic optimization control is derived for reducing seismic response based on the mode analysis in Chapter 3, and the simulating control analysis is made for a simple sample of cantilever beam.The simulating control analysis are made, in Chapter 4, for two samples of cable-stayed bridges using the algorithm of linear quadratic optimization control for reducing the seismic response based on the mode analysis.The algorithm of sliding mode control is derived in Chapter 5 for reducing seismic response based on the mode analysis, and the simulating control analysis is proceeded on the same simple sample of cantilever beam used in Chapter 3.The simulating control analysis on two samples of cable-stayed bridge is carried out in Chapter 6 using algorithm of sliding mode control for the reduction of seismic response based on the mode analysis.Through this study, it is feasible to use the control technology based on mode analysis, both the linear quadratic optimization control and the sliding mode control. The sliding mode control, which is better than the linear quadratic optimization, achieved ideal control result by using comparatively less external energy. The sliding mode control method is valuable to study.