Study on the secondary stresses of joint effects in transmission tubular towers

Abstract

Transmission tubular towers are widely used in urban and large span transmission network, analyzed as ideal frame-truss systems without explicitly considering slippage effects in bolted joints. In this paper, a special beam element considering bolt slip effect is established based on the secondary development module UPFs provided by ANSYS software. A series of semi-rigid model of transmission tubular tower with different parameter features are simulated by directly calling the special beam elements instead of using spring elements and ordinary beam elements. Distribution form and influence factor of secondary stresses of main members in transmission tubular tower leg considering the bolt slippage effect is analyzed. The results indicate that secondary stresses are mainly related to three factors: the layout scheme of auxiliary members, the main member slenderness ratio, the angle between main members and diagonal members. By contrast, it is found that secondary stresses of two lattices are mainly larger than that of a lattice. Under two lattices the angle between the main member and the diagonal member is the major influence factor, while, a lattice, the secondary stresses are mainly depended on the main member slender ratio. Design suggestions are given based on the analysis results.