Seismic Analysis Of Frame Structure Based On Elastic And Plastic Rotation Demand Of Beam

The frame structure is one of the commonly used forms of building structures.In order to controll the deformation capacity of structure and member effectively,we use three level criterions in normal structures' seismic design while performance-based seismic design in special structures' seismic design.At the beginning of structure seismic design,displacement based seismic design method of the current seismic code sets the displacement of structure as target parameters to control seismic response of structure.However,the deformation parameters of whole structure,which can only give rough reference to the plastic deformation capacity of key members,couldn't control the performance of structural members effectively.In order to realize the performance-based seismic design,it is important to establish the relationship of deformation between the whole structure and member.The following researches were made in this dissertation.1)Based on the analytical solutions of displacement of fixed end beam,the relationship between the elastic story drift and the elastic deformation of member was established under the basic calculation assumption of frame structure in structural mechanics;2)Based on the beam-column subassemblage model,the rules of drift decomposition were developed,and the relationship between the elasto-plastic story drift and the elasto-plastic deformation of member was established;3)By introducing The reduction coefficient ? as a parameter,the rules of elasto-plastic drift decomposition are developed.A simplified method was proposed to estimate the plastic rotation demand of the members on the basis of the results of elastic analysis.Furthermore,formulas to calculate the beam plastic rotation needs were given;4)The static elasto-plastic analysis by SAP2000 software and the elasto-plastic time history analysis by ABAQUS software were applied to three single specimen frames,and Seismic performance evaluation of frames were made.Compared with the elasto-plastic analysis results,the relationship between the elasto-plastic story drift and the elasto-plastic deformation of member and the formulas to calculate the beam plastic rotation needs were verified.The results showed that the the proposed method can satisfy the required precision of engineering and can applied to the seismic design of RC frame structure.