Research On The Mechanical Properties Of New Fabricated Concrete Beam-column Joints

With the development of China's residential industrialization and modernization,prefabricated concrete building structures have become one of the important structures in the future construction industry.However,the problem of beam-column connection is an important factor restricting the development of prefabricated concrete structures.In prefabricated frame structures,beam-column joints are the most important joints,which directly affect the seismic performance of prefabricated concrete structures.In view of the above background,this paper summarizes the research status of beam-column joints in prefabricated concrete structures at home and abroad and the current application status at home and abroad;summarizes the existing joint connection forms of prefabricated monolithic concrete structures,and analyzes their advantages and disadvantages.Taking a project example as the background and combining the actual conditions of the project,the joint connection form of the project is researched.Two new types of prefabricated beam-column connection methods are proposed.Using ABAQUS finite element software,the two prefabricated nodes are separately analyzed.Modeling and analysis of cast-in-situ concrete structures.The performances of the nodes under the effects of vertical cyclic reciprocating loads are studied such as the bearing capacity,hysteresis curve,skeleton curve,stiffness degradation,ductility,energy absorption and energy dissipation capacity.The following conclusions are obtained through a series of studies:(1)Both new assembly nodes show higher performance advantages.The comparative analysis shows that the load-bearing capacity of assembled nodes is large,the strength degradation at the same level is not obvious,and the ductility is good.It shows that these two new types of assembled concrete beam-column joints can meet current building requirements and have broad application prospects.(2)From the perspective of stiffness degradation,the stiffness of cast-in-situ structures is greater than that of prefabricated concrete structures,but the stiffness of prefabricated concrete nodes is not much different from that of cast-in-place joints,indicating that the design of the two prefabricated concrete beam-column nodes is reasonable.(3)Through the finite element simulation analysis of assembled node 1 and assembled node 2,it is found that the assembled node 2 has a larger bearing capacity,less strength degradation,stronger energy absorption and energy dissipation capabilities,and weaker ductility and earthquake resistance.But the performance is equivalent to in-situ casting,which meets the requirements.