Semi-active Variable Damper Control Of Steel Mega-frame With Suspended Floors

The huge structure with suspended substructure is a new structure system which has the good vibration reduction performance, this research is gradually becoming the hot spot of resist earthquakes domain research to our country.Because the semi-active controls have many advantages on both active control and passive control,and based on the former's study, this thesis takes work on the vibration control of active variable damper on steel mega-frame with suspended systems.Combining with the cases, it processes the analysis of optimal control for the damping devices installed three different ways of changing the structure of system,and then compares the optimal contorl effects of the three damping deveces.Firstly, in this thesis the equivalent model simplified analysis method is used to analyze the simplified model to the steel mega-frame, it greatly reduced the computation cost; Through analyzing on and comparing the dynamic analysis between the steel mega-frame structure with suspended floors and the pure steel mega-frame structure example, it is obtained some conclusions that the suspended floors in the steel mega-frame structure with suspended floors is advantageous in vibration reduction performance;Then the MRF dampers are changed separately in the different position:â‘ Between sub-structure and sub-structure;â‘¡Between main structure and sub-structure;â‘¢Between main structure and sub-structure, sub-structure and sub-structure; the vibration control of the structure is carried on to three examples which based on three kind of established way above,by using the damping semi-active control theory based on the LQR initiative control;The example analysis indicated that, in three control device established way, when the control device is established between the main structure with the sub-structure, the sub-structure with the sub-structure, the great vibration reduction effects of the steel mega-frame structure with suspended floors is better, particularly the acceleration vibration reduction effect.At the same time,in the thesis it is also proposed the research question which need going into, for example: the consideration and countermeasure to time lag; the consideration and processing to structure non-linear effect; the location optimizations of controller ect.