Study On Seismic Performance Of Self-centering Precast Concrete Frame Joints

From the point of view of structural damage in previous earthquakes,the damage of fabricated frame structures is mostly concentrated on the joints of beam column connection,and the joints are related to the safety and seismic performance of the whole structure,which is the most vulnerable part of the frame structure.Therefore,the joints is the key part of the design of the assembled concrete structure.The self-centering precast concrete frame joints are used in the "ductility connection" method.The joints have reasonable structural design and make the connection parts have better rotation ability.The elastic-plastic deformation of structures under earthquake is expected to be concentrated on the joints,while the beams and columns remain basically elastic.Through the rebound effect of the prestressed reinforcement,the self-centering ability is provided,which makes the residual deformation of the structure small and easy to repair after the earthquake.In this paper,the seismic performance of the self-centering precast concrete frame joints is thoroughly analyzed by using the finite element software ABAQUS.Fristly,the paper studies the principle of node design.Subsequently,the structural design,performance analysis and research plan of self-centering precast concrete frame joints are introduced in detail.The design and calculation method of prestressed tendons are introduced.It provides a theoretical basis for the application of joints in future practical projects.Secondly,in order to study the mechanical properties of self-centering precast concrete frame joints to meet the requirements of seismic resistance in practical engineering,the joints model is established by using the finite element analysis software ABAQUS.The hysteretic curve,skeleton curve,energy dissipation capacity,stiffness degradation and ductility performance of the joint under low cycle reciprocating load are analyzed.The results show that the energy dissipation effect of this joint is good,and it has better bearing capacity,stiffness and ductility.Finally,the paper are established 3 groups of 8 nodes.The influence of each parameter on the seismic performance of self-centering precast concrete frame joints is studied by taking the tensile stress,axial compression ratio and concrete strength as parameters.The results show that the tensile stress of the prestressed reinforcement can improve the seismic performance of the joints.The increase of axial compression ratio in a certain range can improve the seismic performance of the joints,but the effect is not obvious over a certain range.The concrete strength has a certain influence on the seismic performance of the joints,but it is not obvious.