Research On Seismic Design Method Of Steel Frame With Hysteretic Dampers Made Of Low Yield Point Steel

Earthquake is the most serious paroxysmal natural disaster for people. It's urgent to takeeconomical and effective measurement in improving the aseismatic capability of buildingwhich have been built or will be built, especially for our country, a LDC where earthquake isfrequent. The passive energy dissipation systems, which developed in these thirty years, is oneof the practical measurements which are up to the mustard. Although the study of passiveenergy dissipation system had much achievement in both theory and experimentation, there issome distance for application. The main reason is empty of simple,precise and apt to acceptby engineer.In this paper, the methodology of seismic design that based on response spectrum methodfor steel structure with hysteretic dampers was proposed. The difference of the seismic designmethod was the confirmation of seismic effect factor of structure with hysteretic dampers. Theconfirmation of seismic effect factor according to the energy theorem, the response spectrumreflects the reduction effect of seismic response in the structures combined with hystereticdampers because of hysteretic damping; and the variation of apparent natural period producedby increase of damper plastic deformation.A 6-story frame with hysteretic dampers was designed by this design method. It is certain thatthe main frames will be in elastic region under earthquake when dampers are installed intostructures according to this design method. Not only through the design calculation, after thestructure installed the steel dampers to save certain steel products, the structure distortion isreduces obviously, showed the ultra-low-yield-point steel dampers had the remarkable seismicresponse mitigation effect. Besides concise design approach, the design method has powerfulapplication and operability.At the same time, it is analyzed in pushover analysis with SAP2000 finite-elementanalysis program. 2 different frames which are moment-resistant frame and passive energydissipation system were analysised. Lateral load patterns are applied to compute the structure'sbase shear-top displacement curve, and the capacity spectrum method is employed. The resultsshow that the design method for buildings equipped with passive energy dissipation systemsadvised in this paper are reliable. The results got by the pushover analysis prove that thepassive energy dissipation equipments can reduce the earthquake actions in the moderate andmajor levels earthquake effectively.Carries on the confirmation with the power time interval analysis to the example structure.Uses inspires the method of superposition to carry on the multi-degree of freedomelastoplasticity earthquake to respond the analysis. Forms the unit stiffness matrix and the overall stiffness matrix after the known node information, carries on the dynamic performancecomputation, the use inspires the method of superposition to transform the multi-degree offreedom power computation the single degree of freedom the power computation. Theelastoplasticity earthquake responded the analysis result indicated, suggests the design methodaccording to this paper to carry on the ultra-low-yield-point steel dampers structure theearthquake resistance design, meets under rarely the earthquake function its main bodystructure basic maintenance elasticity, can achieve the anticipated earthquake resistancefortification goal, further proved this design method has the strong reliability.