On the Buckling Strength of Angles in Transmission Towers

Abstract

It is assertained that buckling or instablility of angles has been the main cause of destruction of the super-structure of transmission towers due to typhoons. Experimental studies are made of buckling strength of angles, using structural steel with a L-90 mm×90 mm×7 mm profile. Various eccentricities and slenderness-ratios are included. Behavior and modes of buckling failure are observed. Test results are compared with buckling theories, and a general consensus is reached between them. As an approach for safe and economical design of steel transmission towers, safety factors are examined for actual angle members based on the experimental results of the carrying capacity. Revision of JEC allowable stress is proposed.