支撑柱刚度对新型有控结构的风振响应研究

Investigation of Wind Vibration of the Additional Columns Stiffness Ratio on the Mega-sub Controlled Structure

针对一种带附加支撑柱的新型巨-子型有控结构(MSCS),建立了随机脉动风载下的动力方程,基于复模态理论,推导了MSCS在随机风载激励下的协方差函数、位移及加速度均方响应表达式;通过频域分析,讨论了附加支撑柱刚度比对MSCS风振响应的影响规律及其机理,对结构时域内的风振分析验证了频域分析的结论。研究结果表明:在子结构顶层和巨型梁结构层之间设置支撑柱,不仅能解决巨型梁的大跨度问题,而且能减小子结构的位移和主、子结构的加速度响应,当附加柱刚度大于一定值时,结构响应变化不大。工程设计时应综合考虑控制效果和安全性,选择合适的附加支撑柱刚度比。

To solve the problem of the mega beams and the corresponding mega-beam-storey elements that are needed to support the heavy, flexible substructures, a new mega-sub controlled structure （MSCS）, in which the additional columns are introduced at the top-level of some substructures, is investigated. Dynamic equations and methods to assembling parameter matrixes for the meg-sub controlled structure under random wind loads are presented. The coherence function, vibration displacement and acceleration mean square response expressions are derived based on complex modal analysis theory. The influence rule and mechanics of the additional column stiffness ratio on the MSCS is discussed by frequency domain analysis. The results of frequency domain analysis are verified by time domain history analysis. The results preliminarily show that the additional columns configuration can not only overcome the practical design difficulties associated with the large span mega-beams, but also reduce the displacement of sub-frame and the acceleration of mega-frame and sub-structure. When the value of additional column stiffness is bigger than a certain range, the response does not change obviously. In engineering design, we should take controlling effectiveness and security into account to choose a suitable additional column stiffness ratio.