Mega - Sub Controlled Structure System Fluctuating Wind Induced Vibration Analysis

Expediting of citification spurs swift-developing of super tall buildings, which is response to issues during city developing, such as population, land-value and lack of land. New structural forms are required to satisfy structural functions and to control vibration as height of buildings increased. Mega-sub controlled structural system combined conventional mega frame structure and TMD theory, thus it can reduce structural vibration effectively and meet function demands simultaneouslyA new mega-sub controlled structural system is presents in this paper on the base of former research to solve the long span problem of the mega beam, which is achieved through setting additional columns. This paper describes the vibration equation of this structural system, and derives the horizontal vibration displacement and acceleration response spectrum and the mean square response on the base of the complex modal analytical theory. Consulting the structural form of the NEC Building and TC Building in Japanese, numerical examples with three or four mega floors are described. Impacts of additional columns stiffness and additional dampers , which are the important factors to the structural system under pulsating wind , are analyzed through changes of stiffness ratio and damper ratio. Impacts of additional columns stiffness on the mega structure and the sub structure without damper are discussed , and particles of the structural system that have stronger responses are as examples to investigate impacts of damps on the mega-sub controlled structure system. The case that the mega structure undergoes pulsating wind solely is considered as well as the case that the. mega structure and the sub structure undergo pulsating wind simultaneously. Analytical results show that the mega-sub controlled structural system with additional columns can reduce the structural responses effectively and the effect will be better if the mega structure and the sub structure undergo pulsating wind simultaneously. The additional columns can decrease the peak responses of the sub structure and the advisable value of stiffness ratio is 0.3. Responses of the mega structure and the sub structure are reduced when additional dampers are installed and the advisable value of the damper ratio is 2 to 4. On the base of numerical analysis and simulation theory the primary design project of the mega-sub controlled structural system modal is described in this paper.The mega-sub controlled structural system with additional columns is good for vibration control and the long span problem of the mega beam is solved simultaneously. It's easier to realize in engineer.