The Intelligent Control For Seismic Effect Of Three-Gorges Ship Lifter And The Research On Rigidness Of Bolted Joint

Three-Gorges ship lift structure is one of important navigation facilities in the Three-Gorges Projects.As far as its scale for navigation,its lifted weight and height are concerned,the ship lift structure is the greatest one in the world.In this paper taking the ship lift structure as background,the principle of MR adaptive reduced vibration control system is proposed to solve the problem of seismic whipping effect of the top machinery building of ship lift structure.Generally ship lift structure is consisted of two or four huge reinforced concrete tube towers and a single-story machinery building on the top of tube towers.Because the tube towers is demanded to support the large loads,the lateral stiffness of tube towers is a few hundred times as solid as that of the top machinery building and cause the sudden change of the stiffness.This change would cause insentive seismic whipping effect of the top building.The aseismic methods are difficultly used to reduce seismic responses of the top building of ship lift structure.The feasibility of develop an intelligent vibration control system is explored in the paper.Based on the dynamic analysis of the three-dimensions finite element model of Three-Gorges ship lift structure,the equivalent reduced mechanical model is established.The comparisons beween the dynamic characteristics and seismic response of these two models demonstrate that the reduced mechanical model can be used in the research on the seismic whipping effect control in the top machinery building of the ship lift structure.The concept of the roof MR intelligent isolation system is presented in this paper,and this control system to the ship lift structure is applied to reduce the seismic whipping effect in the top machinery building.A modified Bingham model is proposed to simulate the mechanical model of a controlled ship lift structure with roof MR isolation systems is established.Consequently,the dynamic equation of the controlled structure system is obtained.In this paper the fuzzy semi-active control strategy is proposed. The simulation analysis modules with simulink of time-travel curve,fuzzy control and semi-active control strategy is established.The comparisons of passive isolation control, passive-off control, passive-on control and fuzzy semi-active control show that the roof MR isolation system is a valid and practical intelligent semi-active control system.The roofMR isolation system is quit valid in suppressing the seismic whipping effect of the top machinery building.The research is carried on the drop of bending rigidness if bolted joint loose and the equivalent reduced mechanical model is established.The comparisons beween the finite element model and the reduced mechanical demonstrate that the reduced mechanical model is right. Some results are drawed through research.It is carried out to provide bases for establishing the damage detection system in the paper.