Theoretical And Experimental Research Of Circular Tubular Joints

With the advantages of beauty, lightness and rational design concepts, steel tubular structures have got a wide application in China now. These years, with the development of steel structures, the size of steel tubular joints applied in big-span steel structures become larger and more complex. However, the code can not figure out these design problems absolutely. It makes good sense to launch a research of the properties of the steel tubular joints and find a study method in order to throw light on practical projects. In this paper, the project of the stadium is considered which is built in Huazhong University of Science and Technology. Comprehensive researches for the steel tubular joint used in the stadium steel roof are conducted by using the finite element method and full scale test. The research results provide warranty for design. To begin with, systemic summarizations and analysis are given about the static performances of steel tubular joints. Experiments and theories of steel tubular joints are introduced. Then, an ideal elastic-plastic material is assumed, along with the material and geometry being considered nonlinear, the Newton-Raphson increment iterative method and displacement convergence criterion for a solution. From these, one kind of finite element calculative method for computing the bearing capacity of tubular steel is built up. Based on the theory of nonlinear finite element method, finite element model is established by using four-node shell element(shell143). Elastic-plastic large deflection analysis is conducted with the finite element program named ANSYS. The distribution of stress, plastic-zones spread and deformation of the tubular joints are analyzed. The ultimate strength of the joint is found. At last, full-scale experimental research on circular tubular joints of stadium steel roof is carried out. Through the comparison of the test results and finite element results, the finite element calculation method used in this paper is proved accurate and viable. The analysis method and test results for the multi-planner joints will be more valuable for similar projects.