The Research On The Seismic Behavior Of Linked Column Steel Braced Frame With Friction Energy Dissipation Column Base

Linked column steel braced frame is a new type of structure with recoverable function.In order to increase the degree of shear deformation of link beam and energy dissipation capacity,the column foot was designed as lifting column foot,the friction damper was sat at the foot of the column.Under the action of frequent earthquakes,the friction damper does not slide and the foot of the column is considered to be fixed edge.The structure has great stiffness.Under the action of basic earthquakes,the friction damper overcome friction and slide and the foot of the column can lift up.The shear deformation of the link beam is increased,and Energy dissipation capacity of the link beam is fully demonstrate.After the earthquake,the destruction of the structure is only appeared in the link beam and the other components is flexible.By replacing the link beam,the function of the structure can be quickly restored.In this paper,the combination of experiment and finite element analysis is used to research the seismic behavior of linked column steel braced frame with friction energy dissipation column base.The main research content are as follows:(1)A single-span with three-story linked column steel braced frame with friction energy dissipation column base is designed.Then,the structure is fabricated for low-cycle reciprocating loading experiments.Replace the link beam and do experiment again.Analysis the hysteretic behavior and failure mechanism.The research result showed that the seismic behavior of the structure is great.Set up the friction energy dissipation make the shear deformation of link beam increased.The destruction is only produced in the link beam.After replaced the link beam,the structure still has enough stiffness.(2)A new type of friction energy dissipation damper is designed,and The paper used ABAQUS to establish models of the linked column steel braced frame with friction energy dissipation column base,and quasi-static load was conducted on the models.In order to analysis the influence of design parameters such as linear stiffness ratio between link beam and brace on the hysteretic behavior and failure mechanism,the size of brace and length of link beam was changed.The research result showed that linked column steel braced frame with friction energy dissipation column base has significant yield sequence,the link beam develop plastic state fully.Energy dissipation capacity of the structure is excellent.The brace has little influence to energy dissipation of the model.The size of brace should not be large,otherwise the column foot will enter the plastic state preferentially.The size of brace should not be small,that will cause the buckling of the brace.The link beam is main component of the model.As the height of link beam increases,the stiffness and bearing capacity increase,and the energy dissipation capacity increase.Therefore,the height of link beam should not be too low.The linear stiffness ratio of link beam and brace should more than or equal to 160.Within this range,the brace will not cause the buckling before the link beam failure.(3)The link beam with long-hole web is used to replace the link beam with stiffness,and use ABAQUS to research the aspect ratio of column between holes to web and the thickness of the link beam web.The research result showed that linked column steel braced frame with friction energy dissipation column base has significant yield sequence.The link beam with long-hole web is easier to occurs plastic deformation.The aspect ratio of column between holes to web should between 1.4 and 1.6.The link beam is the main component to dissipate energy of the structure,and the web should not be too thin.