Mechanical Properties Research On Fabricated Joints Of Square Steel Tubular Columns And H-shaped Steel Beams With Alteable Beam Depth

Assembly steel structure is an important development content of the construction industry,it has a series of advantages such as a high degree of industrialization,short construction period,low operating environment requirements,easy to rebuild and disassemble,especially steel itself has light weight and high strength,high space utilization,excellent performances of seismic resistance and recyclable characteristics.Its developments are in line with national policy guidance of environmental development having great economic and social significance.In order to address the assembling problem between square steel tubular columns and H-shaped steel beams in fabricated steel structures,a new beam-column joints of fabricated frame is systematically studied in this thesis.The main contents are as follows:(1)Structural and test design of new-type fabricated jointsAiming at the problem of assembling connection between square steel column and H-shaped steel beam,a new type of prefabricated semi-rigid steel frame beam-column joint is proposed,which is more adjustable and more general.Based on its detailed structure and on-site erection scheme,the overall design of full-scale test is put forward.Furthermore,the refined finite element model of new-type fabricated joints is established,as well as the numerical simulation of static loading test is conducted,which provides a theoretical foundation for experimental design.(2)Static test of new-type fabricated jointsTo investigate the static behaviors of fabricated joints,two static tests of 300 mm and 400 mm beam-high were carried out,and the test phenomenon was described in detail.In addition,the strain on critical positions,overall deformation and the failure mechanism are analyzed.Finally,the bending moment curves of each joint are given,and the important mechanical properties such as the initial stiffness,strengthening stiffness and ultimate bearing capacity of the joint are obtained,supporting the experimental basis for further improving design theory of the new joint.(3)Hysteretic test of new-type fabricated jointsTo investigate the hysteresis capacity of fabricated joints,as well as the working performance of dilated hole,2 hysteretic tests of 300 mm and 400 mm beam-high is carried out.The experimental phenomena and damage modes of the joints during the reciprocating loading were analyzed in detail.Finally,the joint hysteretic performancecurve,the skeleton curve and the stiffness degradation curve,the joint ductility coefficient,the energy dissipation coefficient and so on were obtained,and the seismic energy dissipation performance of the joints was evaluated,which could provide reference for the seismic design...