Study On The Seismic Performance Of New Type H-beam To Square Tubular Column Semi-Rigid Connection Steel Frame

At present,the fabricated steel structure is developing rapidly,and the drawbacks of the traditional welded joints that are not conducive to construction and poor seismic performance are becoming more and more obvious.There is an urgent need to develop new types of joint to meet the needs of practical engineering and further promote the development of fabricated steel structure.This paper introduces a new type of square steel tubular column-H steel beam semi-rigid joint,which is applied to the frame to study its seismic performance.The new semi-rigid connection steel frame has been carried out by full-scale quasi-static test and numerically simulation to study its failure characteristics,hysteresis behavior,strength and stiffness degradation,ductility and energy dissipation performance.The influence of different parameters on the seismic performance of the new semi-rigid connection steel frame were also studied.There has also established a three-dimensional new semi-rigid connection steel frame model to study its performance under multiple and rare earthquakes to give references for the practical engineering application.A quasi-static test has been carried out by applying a low-cycle reciprocating load along the beam axis direction to the full-scale new semi-rigid connection steel frame to study its failure characteristics and mechanism,stress-strain law,hysteresis behavior,strength and stiffness degradation,ductility and energy dissipation capacity.The test results show that: The new semi-rigid connection steel frame failure mainly occurs in the panel zone—the grooved beam and the outer sleeve weld crack,H-beam buckling deformation,and the deformation of the outer sleeve and the column flange;the hysteresis performance is good,the bearing capacity is high,The ductility and energy consumption are excellent,the strength degradation is unconspicuous,and the stiffness degradation is stable.The finite element model consistent with the test was established by ABAQUS finite element software.The simulation results were compared with the experimental results,and the stress and strain of each part of the frame were analyzed.The results show that the failure mode,stress-strain distribution and seismic performance of the finite element model are in good agreement with the test results.Angle steel and grooved steel beams can effectively move the plastic hinge outward.Based on the benchmark model,another 11 finite element models were built in ABAQUS to study influences of joint type,frame span,frame storey height and axialcompression ratio on the seismic performance of the new semi-rigid connection steel frame.The analysis results show that the new joint can effectively move the plastic hinge from the H beam end to the edge of the grooved steel beam,and exert the energy dissipation capacity of the beam to improve the seismic performance of the frame.The stiffness and bearing capacity of the new semi-rigid connection steel frame are much larger than that of the pure welded frame;the span has a greater influence on the new semi-rigid connection steel frame.The increase of the span can make the plastic hinge of the beam move outward and fully develop,the beam is destroyed before the joint and the energy consumption of the frame is improved;The storey height has a certain influence on the new semi-rigid connection steel frame,the fullness of hysteresis curve,the bearing capacity,stiffness and the energy consumption capacity of the new semi-rigid connection steel frame decreases with the increase of storey height;The influence of the axial compression ratio is particularly significant on the new semi-rigid connection steel frame.Appropriate column axial compression(about 0.2)can fully exert energy dissipation capacity of the beam,which is beneficial to improve the failure mode and seismic performance of the new semi-rigid connection steel frame.However,the excessive axial compression causes the column to break before the beam.Greatly weaken the seismic capacity of the frame.A three-dimensional new semi-rigid connection steel frame model has been established by SAP2000,and its seismic performance under frequent and rare earthquakes have been analyzed.The results show that the deformation of the new semi-rigid connection steel frame meets the requirements of the code,and the seismic capacity reserve under the rare earthquake is high.The first floor feet and the beam ends on the sides of the third storey are weak parts of the structure.Finally,according to the analysis results,the reasonable frame span and storey height,the improvement suggestions of the new type joints and the suggestions of the three-dimensional new semi-rigid connection steel frame design are given,which are used as references for the practical engineering design.