Optimal Design Of Damage Controlled Steel Beam Column Joint

Based on ABAQUS finite element analysis software,a new type of damage controllable steel beam column connection joint is proposed by exploring 47 groups of joints.The end of the short beam is strengthened by expanding the flange at the end of the joint,and the hysteretic performance of the joint is improved by prestressed reinforcement.The web is connected with long strip shaped small cover plate,the flange is connected with weakened flange double cover plate,and the splicing part is bolted with high-strength bolts.Through the research,it is found that the joint can effectively transfer the concentrated stress at the joint of beam and column or the core area of column to the connecting cover plate,realize the transfer of plastic hinge,and provide stable and reliable bearing capacity.Through the study of a series of joints,the paper concludes the necessity of using long strip and small cover plate to connect the web of joints,and determines the basic design model of the design goal through the study of B series of joints.As the basic joint,it systematically studies the relevant parameters of the series of joints,and obtains the influence rules of different factors on the mechanical properties of joints,and gradually determines the relative optimal design Based on these parameters,the optimal joints are determined.Based on 47 groups of models,this paper analyzes the web reinforcement,flange cover plate weakening,flange cover plate weakening,flange cover plate thickness,web cover plate thickness,flange cover plate weakening depth,prestress size,bolt preload size,splicing gap,upper flange bolt distribution,prestressed reinforcement distribution position on the Mises stress nephogram and load displacement of the joint Under the influence of curve,joint dissipation coefficient,mechanical skeleton curve and stiffness degradation curve,the relevant parameters of the joint are selected and a new type of joint is designed.Through the research,it is found that the strengthened web can effectively improve the bearing capacity of the joint,but over strengthening will cause the plastic hinge of the joint can not be effectively transferred;the weakening of flange cover plate can effectively improve the energy consumption capacity of the joint,improve the hysteretic performance of the joint;the arc weakening performance of flange cover plate is significantly better than the right angle weakening performance;increasing the thickness of flange cover plate can significantly improve the bearing capacity of the joint The greater the thickness of the joint cover plate is,the greater the bearing capacity of the joint is.At the same time,the thickness of the flange cover plate can significantly improve the hysteretic performance of the joint within a certain range.When the flange is arranged with double cover plates,the performance of the joint is the best;the thickness of the web cover plate can appropriately improve the bearing capacity of the joint within a certain range;the weakening depth of the flange cover plate has no significant impact on the bearing capacity of the joint However,it can significantly improve the seismic capacity of the joint;the size of prestress can not effectively improve the size of plastic hinge,but can effectively improve the energy consumption capacity of the joint and enhance the hysteretic performance of the joint;the size of splicing gap can not effectively improve the location and bearing capacity of plastic hinge,However,the smaller the splicing joint is,the better the hysteretic performance of the joint will be;the reduction of the number of bolts on the upper flange will not effectively improve the energy consumption capacity of the joint,but will reduce the hysteretic performance of the joint;the number and location of the prestressed reinforcement significantly affect the position of the plastic hinge,the size of the bearing capacity and the hysteretic performance of the joint,and when two prestressed reinforcements on each side are set away from the center line of the beam,the joint shows The expansion flange strengthened joint can effectively improve the position of plastic hinge.The research shows that the new joint can effectively transfer the plastic hinge to the upper and lower flange connecting cover plate,and has good energy dissipation capacity and bearing capacity.It can avoid large deformation or stress concentration of the main load-bearing components of the joint beam column as much as possible.For general damage,the joint can be quickly repaired by replacing the cover plate.