Dynamic Experiment Research And Finite Element Analysis On Semi-rigid Connections Of Cold-formed Thin-walled Steel Frame

The reliability of joint connection affects the holistic properties of steel structures. In traditional analysis and design of steel frames, the joints of beams and columns in a frame are generally assumed rigid or pinned connections. However, the connection properties of steel frame vary between them in fact, so it was called semi-rigid connection. Though the idealized assumption simplifies the procedures of structural design and analysis, it results in the discrepance between theory and practice, unsafety or conservation of structures, and economic irrationality. Semi-rigid connections are provided with nice connection properties, well dissipative capacity, further yielding and ductility allowance as well as steel economization, in this case, semi-rigid connection has become one of economical and reliable connections. Hereby, comprehensive tests and theoretical were carried out to solve problems on semi-rigid connections in the engineering field, semi-rigid connections have become one of the hot research tasks.Cold-formed thin steel has high ratio of strength and weight, and could be made into rational sections with optimum material distribution. If it is used as the main supporting component of multi-story or low-rise steel structures, it will yield good economic returns. Cold-formed steel is not suitable to be welded, its connection properties incline to be semi-rigid when bolt or screw connections are adopted, so it is meaningful to study the semi-rigid mechanic properties of cold-formed thin steel connections. Thus, this paper combines the local standard of chongqing'Technology Specifications of Light Steel Structure Dwellings'and broad domestic and overseas references, studies the semi-rigid connection of cold-formed thin-walled steel frame (double webs, top and seat angle steel connections), applying test research, theoretical analysis and nonlinear finite element analysis:1) According to broad analysis of the semi-rigid beam-and-column connection mechanics of domestic and overseas steel frame, it integrates and describes the initial connection stiffness of semi-rigid joint with double webs upper and lower angles and its formula of moment bearing capacity. Meanwhile, the main factors that affect various connection properties are introduced.2) Full size cold-formed thin C-shape steel joint test. Through three specimens under periodic loading test, under simulating static loading, the strain distribution of the connection units of the joint, the thickness of the plate, the bolt gradation, the thickness...