Experimental Research On The Seismic Performance Of The Bolted Joint In Layer Assembled Steel Frame

In recent years,the layer assembled steel frame is the development trend of the assembly building.Its characteristic is to disconnect the column at the floor joint,and take a functional area of the house as an installation module for layered assembly construction.The development of simple and reliable beam and column joints for layered steel frame assembly is the premise of spreading modular layered steel frame assembly.In this paper,a new bolted joint suitable for connection between H-type steel beam and square steel pipe column is designed.The seismic behavior of the new joint is studied by pseudo-static test.The main content of the paper is as follows:(1)A new type of beam-column joint is designed by summarizing the research status of bolt joint of layered assembly steel frame.(2)The structural design of the new joint specimen and the comparison specimen is carried out,and the test scheme of the pseudo-static test is designed.(3)The experimental phenomena are described and the macroscopic mechanical properties of the joints are analyzed.The following conclusions are drawn: The flange extension port can cooperate with the column deformation and participate in the earthquake energy consumption.The energy dissipation mechanism of the new node is superior.The displacement ductility coefficient of the two nodes is between 2.74 and 3.66,and the carrying capacity of XJD specimen is 50% higher than that of CJD specimen.Both specimens showed the degradation of strength and stiffness.(4)Combing and analyzing the stress-strain data of the two specimens,the conclusion is drawn: The two specimens have different force transfer paths,resulting in completely different strain development degree and development law in the nodal region.The strain development degree of XJD specimen column wall is far lower than that of CJD specimen at the same position,and the new node form has the effect of embedded rib on the column.The strain development degree of the upper side of the beam end joint is much higher than that of the lower side,and the elongation plate of the upper flange is the bearing capacity short plate of the joint.The core area of XJD specimens has higher bearing capacity redundancy.(5)The node connection properties are discussed in depth.Introducing five kinds of common node connection attribute classification and classifies two kinds of specimens rigidly according to different classification.The mathematical models of six commonly used joint moment-angle curves are introduced,a curve model of moment-angle for XJD type node is presented,and the parameters of the curve function are fitted according to the experimental data.