INFLUENCE OF STIFFENER GEOMETRY AND ANCHOR BOLT LOSS ON THE MECHANICAL AND FATIGUE BEHAVIOR OF STREET LIGHTING POLES

Street lighting poles, generally manufactured from galvanized steel, aluminum, or cast iron, play a major role in urban development by ensuring safety, comfort, and aesthetic quality of public spaces. Their dimensioning, particularly at the pole base level, can be performed according to Eurocode 3 - Part 1.8 using the component method. However, these structures are subject to cyclic loading, primarily due to wind, which can generate fatigue phenomena and premature failures, particularly in stress concentration zones such as the pole-base plate junction and anchor rod connections. To improve the resistance of these critical areas, several solutions are commonly considered, including the addition of stiffeners at the pole base and increasing the thickness of the base plate. Nevertheless, the real effectiveness of these measures in terms of fatigue performance requires further investigation.This paper presents a numerical study of the mechanical and fatigue behavior of metallic street lighting pole bases using a three-dimensional model developed in ANSYS Workbench, incorporating all structural components. The results highlight, on the one hand, the influence of the loss of an anchor rod on the structural response of the pole in terms of stress distribution and fatigue life. On the other hand, three stiffener configurations are analyzed to identify the most effective solution for improving the resistance of pole bases.Among the three configurations analyzed, the third model provides the best compromise, using less material while reducing local stress concentrations and significantly improving the fatigue performance of the structure. Indeed, 28% improvement in fatigue resistance in terms of service life is observed in case 3 compared to case 1.