Study On Seismic Performance Of Beam-column Joints In The Externally Wrapped Steel Tube-reinforced Concrete Frame

At present,the fabricated concrete structure is one of the most mature and widely used forms in the fabricated structural system.The connection node of precast beam and precast column in prefabricated concrete structure is the focus of research.At present,most of the joints of prefabricated components still need to use on-site wet operation,or use more complicated connection forms such as prestress.The steel structure has natural assemblability due to the weldability of materials and the application of simple connection methods such as bolts.This article draws on the common connection methods of steel structures.This paper proposes a beam-column dry joint of outer steel pipe-rebar through concrete frame.Carry out seismic performance test and finite element analysis on the specimen.The specific research content is as follows:(1)Design four outsourcing steel pipe-rebar through concrete frame beam-column dry joints and conduct pseudo-static tests.The experimental research variables are the thickness of the outsourcing steel pipe and whether a reinforcing plate is provided.Observe and record the test phenomenon and the final failure mode of the specimen.Through the load displacement data during the loading process of the specimen,the hysteresis curve,skeleton curve,stiffness degradation curve and bearing capacity degradation curve of the node are obtained.Compare the effects of different test variables on seismic performance.The results show that the joints designed in this paper have good bearing capacity and deformability.(2)Numerical analysis of strain gauges at nodes and beam ends.Through the combination of data and experimental phenomena,it is concluded that the failure mode of the node is bending failure.Combining experimental phenomena and data processing results,using plastic hinge theory and virtual work principle to determine the flexural bearing capacity formula of the new type of joint.The calculation results of the formula are in good agreement with the experimental results.(3)Use Abaqus to establish a finite element model for precast reinforced concrete joints.The accuracy of the model is verified by comparing the results of finite element analysis with actual test results.Parametric analysis is carried out through finite element software.Simulate the effect of axial compression ratio and steel strength on the seismic performance of the specimen.