Occurrence of Local Cylindrical Shell Buckling during Ultimate Strength Test of a Full-scale Transmission Tower, and Consideration Concerning Local Buckling Strength based on Reproduction Analyses

Abstract

Transmission towers have been considered to be designed with enough wind-resistance performance, however, it is necessary to re-examine the current estimation methods from the point of load carrying capacity to improve the structural integrity. Steel pipes for main post members of transmission towers have radius-to-thickness ratio of 10-25 and belong to relatively thick cylinders. The purpose of this paper is to investigate the rare local buckling occurred in the main post pipe during the full-scale ultimate strength test, and to clarify the developmental mechanism analitically combining axial force, bending and torsional moments and shearing force in addition to welding residual stress effect. Furthermore, the buckling strength reduction is discussed comparing the case of combined forces with the case of single axial force.