Exploration On Behaviour Of No-Diaphragm And External T-Stiffener Box-Column To I-Beam Connections

With the rapid increase of national economy, steel structures have been applied wildly in our country. Because of the benefits of box-column such as making use of material sufficiently, light weight of the structure, low request of base and so on, the application of box-column to I-beam connections is more and more extensive. If welding diaphragm in the traditional box- column connection, it will be complicated to fabricate and expensive even bad quality, so it is great significance and engineering benefits to research on behaviors of no-diaphragm and external T-stiffener box-column to I-beam connections in this paper. By means of finite element analysis of ANSYS, the behaviors of no-diaphragm and external T-stiffener box-column to I-beam connections such as initial stiffness, resistance and hysteresis are analyzed. The main contests are listed as follows:Firstly, both of the finite element models are built up. Feasibility and validity of finite element methods are verified by comparison with experiment results closely.Secondly, the models of box-column to I-beam connections without diaphragms are elastic-plastic analyzed under symmetrical static loading. The effects of several factors (thickness of column, flange width and web height of beam.) on initial stiffness, ultimate moment resistance and stress distribution of connections are studied, while the parameters of initial stiffness expression are amended. The connection without diaphragm usually fails by the yield-line mechanism on column flange, so it is weak in terms of low initial stiffness and resistance.Thirdly, the models of box-column to I-beam connections stiffened externally are elastic-plastic analyzed under symmetrical static loading. With the change of thickness of column, dimension of beam and length of stiffener, the behaviors of the connections are investigated, while the expression of initial stiffness is gained. The plastic-hinge which appears in the end of stiffener on beam flange results in greater initial stiffness and resistance even rigid joints. When the optimum length of stiffeners limit the angleγmade by the stiffener...