Study On Magnetorheological Damper-building Control System Based On Imperialist Competitive Algorithm

To improve the seismic performance of structure and reduce dynamic effect,subjected to dynamic hazards such as earthquakes,is one of the important subjects that civil engineers must face.Structural vibration control can effectively reduce the structure response of the building under dynamical hazards and can effectively improve the earthquake resistance of structures.The semi-active control has both reliability,simplicity of passive control system and effectiveness of active control system,and is considered to be one of the most promising structure control technologies..Compared with other semi-active control devices,semi-active control based on magnetorheological(MR)damper has simple structure,continuous adjustable damping force,fast response,large output,good durability,low electricity power,and good seismic performances.Based on building structure model,the structure vibration control using fuzzy logical control(FLC)is studied through experiment and numerical analysis.Imperialist competitive algorithm(ICA)is used to optimize the fuzzy controller.First,FLC is used for the dynamic characteristics of MR with strongly nonlinear relationship,and ICA is used to optimize the fuzzy controller.A fuzzy controller used for MR damper-building system is designed based on the strong robustness and adaptive ability of FLC.Considering the complexity design of fuzzy controller,and avoiding the weakness of ordinary design which the parameters of FLC is chosen by expert experiences,ICA is proposed to optimize the membership function,control rules and quantitative factors.Then,MR damper-building control system for a classic three-layer framework model is established.To minimize the structure response under seismic excitation,a multi-objective function considered both building structure safety and comfortability of residence is designed,and ICA is used to get the optimal parameters of FLC.The control effect of the proposed method is compared with other control strategies,and the advantage of the control method is analyzed.In addition,the mechanical properties of a MR damper is tested by electro-hydraulic servo fatigue machine and the dynamic model of the MR damper is established.The characteristic curves of force-displacement and force-velocity are obtained through the test of MR damper under different operating conditions.In order to determine the best mechanical model for the MR damper,parameters of classical mechanical models are identified and fitting effectiveness of the models are analyzed.Finally,a three-layer steel frame structure is designed and a test platform is built to test the proposed method.The main parameters of the model are analyzed,and systems for fuzzy control,data acquisition,processing,storage,and display are designed.The control effect of different control strategies are studied under seismic excitation.The innovation of this article is that ICA is used to optimize the fuzzy logical controller and the control strategy is applied to fuzzy intelligent control.On this basis,it is applied in building structural vibration control combined with semi-active control based on MR damper.Combining numerical analysis and experimental study,a new strategy is proposed to improve the seismic performance of building.