Wind Vulnerability of Flexible Outdoor Single-Post Billboards

Increased temperature due to global climate change is increasing the magnitude and frequency of extreme winds making billboard structures more vulnerable. This paper proposes a methodology to determine the structural safety of flexible outdoor single-post billboards. A CFD model of a flexible single-post billboard was performed as an example. Resultant wind forces were obtained for the previous model using different wind speeds. A mechanical numerical model of the billboard was realized, and this was subjected to the resultant wind forces. Internal forces for the most vulnerable places of the billboard were obtained for all different adopted wind speeds. Next, a reliability analysis of the billboard was performed considering several values for the bias factor and coefficient of variation for the internal forces caused by wind. Safety levels determined from the reliability analysis indicate that a billboard designed with a nominal wind speed of 180 km/h cannot achieve the target probability index of 3.2 for wind speed higher or equal to 200 km/h for any of the adopted probabilistic parameters. Significant differences in the found safety levels for the evaluated probability parameters indicate that billboard structures could undergo safety values below the target one with changes in the case where wind characteristics endanger this type of structure.

Automated summary

Increased temperature due to global climate change is increasing the vulnerability of billboard structures to extreme winds. This paper presents a methodology to assess the structural safety of outdoor single-post billboards. Computational fluid dynamics (CFD) modeling was used to analyze the wind forces on a flexible single-post billboard. The resulting forces were then applied to a mechanical numerical model of the billboard, and the internal forces at the most vulnerable points were evaluated. Reliability analysis showed that billboards designed for a wind speed of 180 km/h cannot meet the target safety index of 3.2 for wind speeds equal to or greater than 200 km/h, indicating potential safety risks with changes in wind characteristics.