Static Performance Of Steel Column Base With Slip-friction Arc Endplates

Steel structure has been widely used at home and abroad for its good performance in previous earthquake disasters,high bearing capacity,environmental protection and many other advantages.However,in the 1994 Northridge Earthquake in the United States and the 1995 Hanshin Earthquake in Japan,the welded joints were damaged to varying degrees,causing great difficulties in post-earthquake repair work and causing high economic losses.Similarly,in the 2010-2011 Christchurch series of earthquakes,although a large number of buildings did not collapse,but the damage is serious and has no repair value.Therefore,it is urgent for the society and the people to carry out the research of damage control structure design to minimize the loss caused by earthquake disaster.Based on this,the research group put forward a new type of steel column base with slip-friction arc endplates,expecting to replace the yield energy consumption of traditional column base joint by the sliding friction energy consumption between arc plates and between arc plates and bolts,so as to achieve the design goal of lossless energy.In this paper,two kinds of steel column base design schemes of "concave" and "convex" proposed by the research group are compared and analyzed in terms of rotation center,initial slip moment,arc plate interface deformation,connection rigidity,etc.Through ANSYS,and further parametrically analyses to investigate the effect of the section size of the column,the thickness and radius of the arc endplates,the number of bolts,the axial compression ratio,and the friction coefficient between the arc endplates on the static performance of the column base influences.The results show that under the same condition of axial compression ratio,the convex joint is superior to the concave joint in terms of rotation center,initial slip moment,arc plate interface deformation and connection rigidity;increasing the thickness of the arc endplates has little effect on the initial stiffness of the joint,and the rotation angle of the joint at the beginning of rotation is almost unchanged,while the initial slip moment and arc endplates interface deformation of the joint are slightlydifferent When the radius of the arc plate is increased,the rotation angle and the initial rotation stiffness of the joint are basically unchanged,and the radius of the arc plate is set between 0.5H and 0.8H,which is more appropriate;the number of bolts,bolt specifications and friction coefficient mainly affect the initial slip moment and arc endplates interface deformation of the joint,but have little effect on the initial stiffness of the joint;increasing the axial pressure can increase the initial slip moment of the joint,which is helpful to the increase of the initial slip moment of the joint improve the friction energy consumption capacity of column base joints.