Mechanical Properties Of Semirigid Connections In Light Steel Modular House Of Assembled Type

Light steel modular house of assembled type was a light steel frame structure,equipped with light maintenance system to meet functional requirements,and can be repeatedly disassembled and assembled modular house.As a resource-saving and environment-friendly building system,light steel modular house of assembled type has been used in hotels,restaurants,exhibition halls and office buildings now.Domestic and foreign scholars have carried out research on light steel modular house of assembled type.However,most of the researches focused on architectural design and mechanical behavior of integral structure.The research on the mechanical behavior of the connection between the column and the top and bottom frames of light steel modular house of assembled type was relatively few.High-strength bolts were used between the column of the light steel modular house of assembled type and the top and bottom corner of frames.Asymmetrical open section was adopted for the column and the top and bottom frames.Therefore,the nut-free high-strength bolts were directly tightened into the end plates of the corner during installation,thereby connecting the columns to the top and bottom frames.Compared with beam-column joints was more complex.In order to understand the mechanical characteristics of joints,the mechanical properties of semirigid connection joints in light steel modular house of assembled type were systematically studied by means of experiments,finite element analysis and theoretical analysis.The main scope of this dissertation include:(1)33 specimens of the connection between nut-free high-strength bolt and end plate were tested under static tension.The influence of the diameter of the high-strength bolt,the material property of the high-strength bolt,the length of the high-strength bolt,the material property of the end plate,and the thickness of the end plate on tensile behavior were investigated.Based on the experimental results,the tensile properties and failure modes of bolt-end plate connections are discussed.(2)The static tension test was simulated by finite element analysis software ABAQUS6.14.Based on numerical simulation and experimental results,a double-fold theoretical calculation model reflecting the tensile properties of high strength bolts without nuts and end-plate connectors was proposed.(3)4 specimens of joints with different lateral constrains and different axial force were tested under cyclic loads.The deformation,failure mode,ultimate bearing capacity,degraded stiffness,energy consumption and ductility of the connection joints of light steel modular house of assembled type were investigated.Meanwhile,the influence of lateral constrains and axial force on semirigid behavior of joints were studied.(4)The finite element software ABAQUS6.14 was used to simulate and analyze three groups of joint tests with lateral constraints.Based on the experiment of joints with lateral constraints and finite analysis results,the initial rotational stiffness of the joint of light steel modular house of assembled type was analyzed,and the type of the joint was determined according to the analysis results.(5)Based on experimental and finite element analysis,a three-parameter power function theoretical calculation model was proposed to reflect the mechanical properties of joints in light steel modular house of assembled type.At the same time,the initial rotational stiffness and ultimate bending moment of joints in the theoretical model were deduced by component method.