Research On Ultimate Capacity Of Cast Tubular Joints And Flange Connection

Tubular structures are constructed compactly with perfect shapes and often applied in large-span steel structures. The tubular joints are the key point in the design procedure of tubular structures. The research on tubular joints is an interesting topic internationally. In this thesis, the loading capacity of cast tubular joints and flange connections is reviewed, Chinese and foreign codes on ultimate capacity of tubular joints and flange connetions are summarized, and Finite element method is applied to carry out the parametric analysis on ultimate capacity of cast tubular joints and flange connections.The research includes:(1)Ultimate capacity of axially loaded cast T and Y-joints. A lot of parametric analysis of cast T-joints is performed in this thesis. The geometry model was established using Solidworks. Non-linear analysis is carried out using the commercial finite element programme Ansys. Parametric equations of ultimate loading capacity derived from the results of finite element analysis are presented for the usual range of basic shapes of T-joints under axial loading. The sensitivity of ultimate loading capacity of cast tubular joints to the fillet parameterρis presented.(2) Ultimate capacity of cast T-joints loaded by bending moment. Parametric equations of ultimate loading capacity derived from the results of finite element analysis are presented for the usual range of basic shapes of T-joints loaded by bending moment. The sensitivity of the ultimate loading capacity of cast tubular joints to variation in the geometric parameters has been assessed.(3) On the basis of yield line theory, the parametric equations for flange connections of the four basic types are derived in this thesis. The design method is developed by simplifying the theoretical formula.(4) On the basis of theoretical formula, the FE analysis on loading capacity of flange connections in circular-tube structures is carried out in this thesis. The design method is developed by simplifying the theoretical formula.(5) On the basis of theoretical formula, the FE analysis on loading capacity of flange connections in rectangular-tube structures is carried out in this thesis. The design method is summarized and evaluated. In the end, the design suggestions are given.Parametric equations of loading capacity for cast tubular joints and flange connections are presented in this thesis. It is theoretical basis for the establishment of relative standards.