Numerical Analysis Of Seismic Behavior Of Self Restoring Beam Column Joint With Cantilever Beam

The traditional structure uses the ductility of the structure itself to make it produce plastic deformation to dissipate the energy produced by the earthquake.It often forms large residual deformation and structural damage after the earthquake,w hich brings many difficulties to the structural repair after the earthquake and causes huge direct and indirect economic losses.It is not enough for a modern structure to take the prevention of life loss as the seismic performance goal only because of the concentration of population,buildings and infrastructure,wealth and social functions in modern large cities.The post earthquake recoverability is becoming a new requirement of seismic design.Based on the concept of post earthquake recoverability,this paper puts forward a kind of beam column joint of steel structure with energy dissipation self resetting of cantilever beam section,which provides a new idea for the seismic design of multi-storey steel structure frame.The main contents are as follows:(1)In this paper,a kind of beam column joint with cantilever beam segment energy dissipation and self reset steel structure is proposed,and a patent has been applied.The connection position of the short cantilever beam and the connecting beam of the j oint is set near the inflection point of the beam under the combined load.Under normal use and small earthquake,the joint is similar to the rigid joint in stress,and the joint of the short cantilever beam and the connecting beam does not rotate relatively;in case of frequent earthquake,the joint of the short cantilever beam and the connecting beam is opened,and the deformation consumption depends on the U-shaped steel damper Under rare earthquake,the U-shaped steel damper completely yields,and the prestressed steel strand remains elastic;(2)Combined with the research status of the self reset joint at home and abroad,the paper studies the energy consumption self reset beam column joint with cantilev er beam section,and puts forward the design method of the energy consumption self reset bea m column joint with cantilever beam section.The hysteretic curve of the joint shows the typical "flag" characteristics of the energy consumption self reset structure.After the relative displacement of the joint,the energy consumption is through the U-shaped steel damper,The prestressed steel strand provides self restoring force,which makes the joint have good self resetting ability and small residual deformation(3)Compared with the traditional steel structure joint,the energy dissipation capacity of the beam column joint with cantilever beam segment is slightly reduced,but not significantly.After the end of displacement loading,the residual deformation of t he joint is significantly reduced,and the main body of the beam column is basically not damaged,The U-shaped steel damper and connecting device can be replaced to restore the use,which is easy to repair after the earthquake;(4)Based on the analysis of the factors influencing the seismic performance of the beam column joint with energy dissipation self resetting of cantilever beam section,under the condition of the same other parameters: increasing the initial pre tightening force of steel strand and i ncreasing the number of steel strand,the stiffness and self resetting capacity of the joint are enhanced,and the energy dissipation capacity is reduced;whe n the thickness of damper U-shaped section is reduced,the stiffness and energy dissipation capacity of the joint are reduced,The stiffness and self reset ability of the joint are slightly enhanced and the energy consumption capacity is decreased with the increase of the steel strand spacing.