Some Advances in the Application of Weathering and Cold-Formed Steel in Transmission Tower

摘要

Application of weathering and cold-formed steel in transmission lines can reduce steel consumption and environmental pollution. Some advances in the studies on the weathering and cold-formed steel in transmission tower are introduced. Firstly, corrosion-resistant tests of weathering steel samples under different simulating technical atmospheres were carried out separately for 240 hours. It shows that the corrosion degree of joint samples is higher than that of single chip samples, and the corrosion-resistant performance of weathering steel is superior to common carbon steel. The corrosion-resistance of weathering steel meets with the requirement of transmission tower. Secondly, experiments and finite element analysis for cold-formed angles and a 220kV prototype tower were completed, and the stability coeffi-cient fitting curves as well as the modification formulas of slenderness ratio for cold-formed members were determined. According to the structural characteristics of transmission towers, four sections of cold-formed angles with different sections and slenderness ratios were selected in this study. The finite element model well predicted the buckling behav-iour of the cold-formed members. Ultimate loads calculating by the fitting curve were well agreed to the experimental values, especially for the members with small slenderness ratios. Weight of the cold-formed steel tower can be reduced by more than 5 percent after considering the strength enhancement. Cost of the weathering and cold-formed steel transmission tower is nearly equivalent to that of hot-rolled steel tower with hot galvanizing.