Mechanical Principle In Crossing Web Member Of Cold-formed Steel Triangular Transmission Towers

The study object in this paper mainly refers to the triangular transmission towers, with cold-formed 60° angle steel column, the crossing web member using four cold-formed cross-section forms :curled equilateral angle steel section, curled C-section, square hollow section and HF welding circular hollow section. This tower structure has better economic efficiency and engineering application prospect, and it is worth promoting and utilizing.The main study achievements in the paper are the following:1. According to four new cold-formed cross-section forms for the towers, The paper discusses general theory method of analyzing thin-walled pole in detail,2. The basic principle of compression bar non-linear buckling analysis with ANSYS software, and formulate constitutive pattern, destroy criterion, choice of material unit and parameter and so on are also been discussed in detail.3. The paper puts forward simplified calculation model of buckling extreme bearing capacity for these four section forms according to the border restrain conditions in the triangular transmission towers .4. It presents ANSYS finite element model of pole with four section forms with shell unit including initial off-center and bending, and analyzes non-linear bucking of axis-pressed bar and off-center press bar respectively, then gets the ratio of extreme bearing capacity corresponding of each sectional form axis-pressed bar and off-center press bar, and gets some suggestions of update reduction coefficient of the code, base on contrast of reduction coefficient between the calculation method and the code.