Vortex Shedding-Induced Fatigue Analysis for High-Mast Lighting Towers.

Abstract

The high-mast lighting towers that are subjected to cyclic wind loadings (due to vortex shedding action) tend to fail due fatigue failure. From past studies, based on the testing and finite element analysis, it was found that geometry of the mast arm and base connection are highly influencing on the fatigue performance of the high-mast lighting towers, and also, the design of this wind sensitive structures is mainly governed by wind-induced fatigue. This study investigates the wind-induced fatigue behavior of high-mast lighting towers under the effect of mast arm wall thicknesses and base connection geometry with unstiffened base connection. The thicknesses of the base plate and the mast arm wall are used as variable parameters, because these are highly influencing on the fatigue performances of the system. Generally, finite element analysis is performed for the selected geometry of the high-mast lighting tower system with various thicknesses of the mast arm wall and base plate to obtain the hot spot stress and SCF with considering along and vortex shedding wind action. Finally, the procedure for a detailed fatigue analysis based on Palmgren–Miner theory of cumulative damage method with S–N curves based on EN 1993-1-9 is discussed.