Experiment Research On Connections Of Cold-formed Thin-walled Steel Frame With Double Webs Top And Seat Steel Angle

The joint of a frame is the keystone in structural design, the stress with a complicated distribution were concentrated in the connection, that makes the node difficult to be designed and constructed. 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. If draws the mechanics model according to the rigid connection frame, that will be over-evaluated the bearing capacity of the structure. And if draws mechanics model according to the pinned connection frame, sometimes, the calculation will be error. So for being rational to predict the bearing capacity of system, it should consider in the analysis and design of the structure the true nonlinearity of the connections, that is the influence of the semi-rigid connection.The thesis were based on the analysis and experimentation of cold-formed thin C-shape steel joint with double webs top and seat steel angle, the main works is following:①According to broad analysis of the semi-rigid beam-and-column connection mechanics of domestic and overseas steel frame, it analyzes and describes the initial connection stiffness of semi-rigid joint with double webs top and seat angles and its formula of moment bearing capacity. Meanwhile, the main factors that affect various connection properties are introduced.②Tested the property of three full size cold-formed thin C-shape steel joints on the one-way load , and focused on the crack mode of the frame node, the distribution of the stress on the node area, the evolution rule of the stress and strain on the steel angle, and the stress status on the joint of frame. The thesis also tested the rigid of the frame connection (tested the M-θ curve) , and summarized the development rules of the stress and strain on these component, also analyzed the trend of the M-θ curve evolution. The suggestion of steel angle with stiffening plate also be given in the thesis.③Through the finite element analyses of the beam-to-column connections.