Hysteretic Energy Analysis Of Concentrically And Eccentrically Braced Steel Frames Under Rare Earthquakes

The elastic design method based on strength,adopted in the current building seismic design code,can not accurately estimate the elastic-plastic performance of the structure,nor can predict the cumulative damage caused by the cyclic effect of ground motions.The energy-based seismic design is known for the consideration of structural strength and displacement,and strong earthquake duration or other factors caused by the ground motion,and can reflect the cumulative hysteretic energy and reciprocating plastic deformation of the structure.Therefore,the energy-based seismic design is a promising design method,and the prediction of hysteretic energy demand is the core content of the energy-based seismic design.In this paper,according to the current code,the 10-storey and 15-storey herringbone concentrically braced steel frame(CBF),single diagonal concentrically braced steel frame,V-type eccentrically braced steel frame(EBF)and K-type eccentrically braced steel frame are designed.Through the use of far-fault earthquake ground motions(EQGM),the nonlinear dynamic analyses of 8 designed structure specimens are carried out using ABAQUS software.Through the analyses,the cumulative hysteretic energy,the hysteretic energy distribution along the structural height and the ratio of hysteretic energy of each component to total hysteretic energy are obtained.According to the results of finite element analysis,the hysteretic energy spectrum and the method for predicting the hysteretic energy demand of steel frame with multi degree of freedom proposed by our research group are evaluated,and the reliability of the prediction method is verified.