Application study on eccentric K-joint with high-neck forging flange applied in steel tube transmission tower

摘要

Minus eccentric connection for steel tube joint could diminish the size of joint board and the windward area. According to investigations in China and other countries, there's no report about study on eccentric K-joint with high-neck forging flange connecting chord member from any research institute or scholar. Consequently, two sizes of steel tubes are selected to design two kinds of K-joint, in which their chord members are controlled correspondingly by intensity and by stability. Based on joint tests and finite element analysis, conclusions are obtained as follows. (1) As to K-joint in which its chord member is loaded by pressure and controlled by intensity, chord members on the side of tension bracing member and in the middle of joint board appear local flections when overloaded 32.5%, while there's no flexion on flange or joint board. (2) As to K-joint in which its chord member is loaded by tension and controlled by intensity, chord member is stretched in length and shrunk in diameter when overloaded 45%, flange plates are distorted slightly, while there's no flexion on flange neck or bracing member. (3) As to K-joint in which its chord member is loaded by pressure and controlled by stability, chord member on the side of tension bracing member is bent in the middle when overloaded 30%, while there's no flexion on flange or joint board.(4) As to eccentric K-joint with high-neck forging flange in which its chord member is controlled by intensity, proper minus eccentricity could diminish the size of joint board and eccentricity barely affects the bearing capacity of chord member, which could be used efficiently. (5) As to eccentric K-joint with high-neck forging flange in which its chord member is controlled by stability, K-joint is mainly bent totally in chord member, while effects on flange and joint are slight. Effects of slenderness ratio and eccentricity on bearing capacity of chord member should be studied further. Study on this new joint type is greatl- advanced, which provides technical support and reference for future research on new joint types of steel tube transmission tower.