Seismic Behavior Of High Energy-consumption Concrete Beam-column Joints

China’s earthquake activity is high in frequency,high in intensity,shallow in source and wide in distribution.It is a country with severe earthquake disasters.Each earthquake will cause a lot of damage or collapse of the building structure.In recent years,with the short construction period,high construction quality,green energy conservation and environmental protection,the assembled frame structure has been formed and developed.At the same time,the concrete frame system is widely used in real life as a common structural form,but many earthquakes The disaster survey shows that the damage of the frame structure is mainly concentrated at the beam-column joints.In order to alleviate the seismic damage of the frame structure,this paper combines the lead-based elastic viscoel damper(LTPVD)based on the lever principle proposed by the research team to improve the cast-in-place concrete frame joint(XJ)and the “loadable and detachable” new loading and unloading beam and column.The seismic performance of the node(ZX),this paper mainly carries out related research in the following aspects:(1)Summarizing the shortcomings of related prefabricated concrete frame structures and energy dissipation technology at home and abroad,the concept of high energy-consumption concrete beam-column joints is proposed,for high-energy-conducting cast-in-place concrete beam-column joints(LDXJ),high The design of the energy-consuming loading and unloading concrete beam-column joint(LDZX)structure is described.(2)By establishing the ABAQUS finite element model,the numerical analysis of XJ,ZX,LDXJ and LDZX is performed by monotonic displacement.The results show that the concrete damage degree of LDXJ and LDZX is the crack ratio of XJ in the core area of the node at the same loading displacement.The ZX is relatively reduced,and the direction of the crack is mainly developed away from the core area(the outer side of the connecting plate of the damper installed on the node).The initial stiffness and bearing capacity of the XJ and ZX are not much different,and the ZX is about 4% smaller than the XJ.,almost "equivalent cast-in-place",to meet the detachable design effect;LDXJ and LDZX initial stiffness and bearing capacity are similar,the bearing capacity difference of about 3%;LDXJ and XJ contrast,LDXJ initial stiffness and bearing capacity is obvious Improve,the bearing capacity is increased by about 43%;compared with LDZX and ZX,the initial stiffness and bearing capacity of LDXJ are obviously improved,and the bearing capacity is increased by about35%.(3)The numerical simulation of LDXJ and LDZX under low-cycle repeated load loading,and comparative analysis with XJ and ZX,to study its stress characteristics and seismic performance.The research shows that the bearing capacity and stiffness of LDXJ and XJ are increased by 1.39 times and 1.42 times respectively,and the energy absorption and shock absorption effect is increased by about 1.5 times;the bearing capacity and rigidity of LDZX and ZX are increased by 1.39 times and 1.59 times respectively.The energy absorption and shock absorption effect is increased by about 1.55 times;(4)Comparative analysis of the influence of different axial compression ratios and lead core number on high energy-consumption concrete beam-column joints,and summarize the change law.The research shows that within a certain range,with the increase of the axial compression ratio and the number of lead cores,the bearing capacity and energy consumption capacity are improved,but the effect is not obvious.