Study On Seismic Behavior Of Steel Reinforced Concrete Joints With Weakening At The Flanges Of Beam Ends

Compared with reinforced concrete structures,SRC composite structures have the characteristics of high bearing capacity,good ductility,and strong earthquake resistance,so it has been widely used in engineering.Steel-concrete structure is mainly used in multi-high-rise buildings.It combines the advantages of steel structure and concrete structure to make full use of materials.In the multi-high-rise structure system,the problem of node processing is of vital importance.Generally,the node core area is strengthened through calculation and the measures to change the structure,so as to ensure the bearing capacity,ductility and seismic performance of the node.This paper attempts to apply DRBS(double reduced beam section)type joints in steel structures to steel concrete joints,combine the two and study their seismic performance.The DRBS section is based on the weakening of the beam-end section of the dog-bone section,and an additional weakening section is added to achieve the purpose of simultaneously entering the plastic zone and protecting the core area of the joint under the action of earthquake.In this paper,ABAQUS software is used as a tool to establish and verify the effective steel concrete joint model,and analyze the joints of different forms,focusing on the analysis of the joints hysteretic curve,skeleton curve,ductility,energy dissipation capacity and other seismic performance.The main results of the study are as follows:(1)DRBS double-weakened SRC joints are better than RBS dog-bone SRC joints and ordinary SRC joints in terms of ductility,energy dissipation and other seismic performance.(2)By changing the design parameters of the DRBS double-weakened SRC joint model,it is concluded that the effect of distinct parameter changes on the seismic performance of the joint is: the weakening length of the second section has no significant influence on the ultimate bearing capacity,ductility,energy dissipation capacity and stiffness degradation of the DRBS double-weakened SRC joint;In the second section,the weakening depth significantly changed the ultimate bearing capacity,ductility and energy dissipation capacity of the DRBS double-weakened steel concrete joint,while the stiffness degradation had a certain effect,but the effect was not obvious.