Comprehensive Analysis On Equivalent Dynamic Characteristics Of Tall Building With FPS-TMD System

From the literal understanding of this sentence in Das Kapital,"The economic base determines the superstructure,the superstructure in turn,act on the basis of economic",it describes the relationship between economic basis and superstructure in narrow sense.With the rapid development of economy,the height of the building has been refreshed.More high-rise landmark buildings springing up,and they have carried the political,economic and cultural core of a city.These super tall buildings have the characteristics in more height,much slender and less flexibility,and wind loading has become the control factor for the structural design of these tall buildings.In this thesis,the Friction Pendulum System which is commonly used in energy dissipation and vibration reduction is organically combined with the Tuned Mass Damper system to form a new type of Friction Pendulum System Typed Tuned Mass Damper(FPS-TMD)passive control system.By adopting the energy method,the combined equivalent linearization and adaptive Genetic algorithm,the equivalent damping ratio and equivalent stiffness of FPS-TMD system are evaluated.On the other hand,the FPS-TMD system is considered to be placed atop of a tall building,the total effective damping ratio of the tall building with FPS-TMD system is obtained by the power flow algorithm.The main research contents are as follows:The mechanical and dynamic properties of the FPS-TMD system are studied and some formulas are derived.Four different friction models are also introduced,which includes unidirectional constant friction coulomb model,unidirectional velocity-based variable friction coulomb model,unidirectional displacement-based variable friction coulomb model and unidirectional variable friction viscoplastic model.The equivalent damping ratio of the FPS-TMD system is derived and calculated according to the principle that the energy consumed by the equivalent viscous damping force in the motion of the FPS-TMD system is the same as that consumed by the work done from the restoring force in the horizontal direction.In addition,the energy method is employed under the circumstances of four different friction models,and the bottom of the FPS-TMD system is subjected to simple harmonic load or random wind loading with different recurrence periods.The effects of amplitudes in external loading,the natural circular frequency for external loading,friction models and friction coefficients on the derived equivalent damping ratio of the FPS-TMD system are studied.The dynamic equilibrium equation of FPS-TMD system and its solution are derived,and the improved adaptive genetic algorithm is proposed in this thesis in detail.The same loading case selected by the energy method are also applied in this section.The equivalent damping ratio of FPS-TMD system is analyzed in detail by the combination of equivalent linearization and improved adaptive genetic algorithm.Meanwhile these analyzed results are compared with the results obtained by the energy method.Taking the wind vibration control Benchmark model of a 76-storey reinforced concrete building as an example,and assuming that the FPS-TMD control system is placed atop of the studied building,the power flow method is adopted to analyze the total effective damping ratio of the wind vibration control Benchmark model when the the studied tall building with FPS-TMD system is modeled by different friction models and it was excited by wind loading with different recurrence periods.The analyzed total effective damping ratios of the studied building with FPS-TMD system are further compared with the equivalent damping ratios of FPS-TMD system deduced by the energy method and the equivalent linearization analysismethod.