Research On Seismic Behavior Of Steel Frame-braced Shear Panel Structure

Steel frame-braced shear panel structure is a new kind of double seismic-resistant system with replaceable shear panel at the center of X-braces.As the main energy dissipation components,the shear panels come into plastic before the frame under the earthquake,and protect the structure of the main body.The braced shear panel is the first line of anti-seismic,the frame is the second one.Through reasonable design,the deformation of the structure can be decreased and the seismic performance can be improved.After the earthquake,the structure can recover its normal function by replacing the shear panel components.In this paper,the seismic performance of steel frame-braced shear panel structure is studied by finite element method.Firstly,one-bay-one-story steel frame-braced shear panel structure models are built and studied by push-over analysis and hysteresis analysis.Its working process and hysteresis performance are studied,and the influence of shear panel thickness and width on structural strength,stiffness,axial force of braces and energy dissipation capacity is analyzed.Then we design 9 multi-story steel frame-braced shear panel structure,verify the correctness of the design method by the push-over analysis of inverted triangle horizontal force.The structural strength,stiffness,structural deformation and shear force distribution under different bay length and story are analyzed,and the seismic performances of steel frame-braced shear panel structure are investigated.Finally,8-degree seismic response spectra analysis and time-history analysis under frequently earthquake,fortification earthquake and rarely earthquake are carried out,the deformation of structure,the distribution of base shear force and the failure mechanism are investigated.The results show that the stages of steel frame-braced shear panel structure come into plastic has obvious timing.The shear panel come into plastic before the frame beam,and finally the bottom of frame column.The shear panel is very easy to replace because the long gap of structure displacement between the plastic of shear panel and the frame come into plastic.The strength and stiffness design of the steel frame-braced shear panel structure is relatively independent,increasing the thickness of the shear panel can improve the loading capacity and stiffness of the structure,increasing the width of the shear panel can improve the loading capacity without changing the stiffness.Under cycle horizontal load,the steel frame-braced shear panel structure has good energy dissipation capacity and the hysteresis curve is full.With the increase of the height of the building,the bending effect of the structure increases,the shear panels at the top are not easily yielding.The results of the time-history analysis show that the structural deformation can be decreased remarkably by setting the braced shear panel.The structural deformation of steel frame-braced shear panel designed by this paper is flexible under frequently earthquake.Under fortification earthquake,the shear panels come into plastic and frame maintains elastic.Under rarely earthquake,the shear panel sand frame beams and the bottom of column come into plastic.The frame play the role of the second line of anti-seismic to avoid structural collapse,satisfy the structural seismic design performance objectives.