Test Research And Finite Element Analysis On Hysteretic Behavior Of Linked Column Steel Braced Frame With Energy Dissipation Column Base

Under the action of earthquake,the link beam of linked column steel braced structure enters the plasticity first,which dissipates energy and prevents major components from entering plasticity.After the earthquake,it is only necessary to replace the energy-consuming link beam in the damage concentration,so that the structure can be quickly repaired to use.The linked column steel braced structure has an ideal failure mode.In order to further increase the degree of plasticity of the link beam,it is proposed to install the link beam at the foot of the column to form a type of linked column steel braced frame with energy dissipation column base.The column base is in contact with the foundation,and the structure is simple,and the vertical deformation is not limited,so as to increase the shear deformation of the link beam under the horizontal load and improve the energy consumption performance of the structure.In this paper,the seismic behavior of the linked column steel braced structure is researched by the combination of experimental research and ABAQUS finite element software simulation.The main research tasks are as follows:(1)The reduced scale specimen of linked column steel braced structure was designed,and the link beam was replaced once.The LCB-1 test piece has the open-hole link beam,and the link beam with stiffener was used in LCB-2 test piece.Preparation,cyclic loading and post-processing work were performed on the two test pieces.From the hysteresis performance,skeleton curve,stiffness degradation,strength degradation,energy dissipation capacity,relative deformation of the link beam,strain value of each component,etc.,the reduced scale specimens of linked column steel braced structure after low cyclic loading were analyzed.The test results show that the link beam of the two test pieces first enters the yield.The link beam and the column base are destroyed successively at the end of the test.The overall structure has strong energy consumption,high bearing capacity and large lateral stiffness.(2)After verifying the test with ABAQUS finite element software,the influence of design parameters such as link beam lengths and brace spans on the hysteretic behavior of the structure was analyzed by finite element software.The results of finite element analysis are as follows:when the web stiffener is used in the linked column steel braced structure.With the increase of the length of the link beam,the bearing capacity and stiffness of the structure decrease,and the energy dissipation capacity of the structure increases first and then decreases.The suggestion on the length of link beam is in the range of(1.0~1.5)M_p/V_p.As the span of the support increases,the structural stiffness increases,and the bearing capacity and energy consumption capacity of the structure are significantly improved.When the long circular hole web is used in the linked column steel braced structure,with the increase of the length of the link beam,the bearing capacity and stiffness of the structure decrease,and the energy dissipation capacity of the structure increases,as the span of the support increases,the structural stiffness increases,and the bearing capacity and energy consumption capacity of the structure are improved.When the long circular hole web is used in the linked column steel braced structure,with the increase of the ratio of length to width of the column between holes in the opening-links,the ultimate bearing capacity,the stiffness,and the cumulative energy dissipation capacity of the overall structure are reduced.It is recommended that the ratio of length to width of the column between holes should be 1.1~2.1.