斜拉桥结构基于模态分析的减震控制

斜拉桥结构是新型的大跨柔性结构,这种桥梁不仅造价低、造型美,而且跨越能力大,已得到国内外学者和工程技术人员的重视。近些年人们对其结构分析和抗震设计方面予以较多的关注。另一方面,建筑结构的振动控制已取得了许多研究成果,但对斜拉桥结构的减震控制的研究还非常薄弱。正是基于此,本文开展了对大跨斜拉桥结构基于模态分析的减震主动控制研究。本文的主要工作如下:第二章建立了斜拉桥结构震动控制的分析模型,分析了两个斜拉桥算例未控时动力性态和地震响应,在地震响应分析中运用了改进的振型叠加法。第三章推导了基于模态分析的线性二次最优控制算法,并对一个简单伸臂梁算例进行了仿真控制分析。第四章运用基于模态分析的线性二次最优控制算法对两个斜拉桥算例进行了仿真控制研究。第五章推导了基于模态分析滑动状态控制算法,并对第三章的算例进行了这种算法下的仿真控制研究。第六章运用基于模态分析的滑动状态控制算法,对两个斜拉桥的算例进行了仿真控制研究。研究结果表明:本文采用的基于模态分析的控制技术,无论是线性二次最优控制还是滑动状态控制是可行的。基于模态分析的滑动状态控制比线性二次最优控制用较少的外部能量可得到较好的控制效果,基于模态分析的滑动状态控制是一种有研究、开发价值的控制算法和控制方法。
电加热器
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.