Abstract
The objective of this study is to estimate the maximum peak wind force coefficients on rooftop signboards more reasonably. The maximum peak wind force coefficients for I-shaped signboards installed on one side wall of a building were measured through systematic wind pressure measurements, in which parameters such as building shapes, signboard shapes, and installation positions were changed over a wide range. The most critical area for the wind resistance design is the edge of signboard, where the maximum peak wind force coefficient occurs at oblique wind directions relative to the signboard. Flow visualization focusing on these wind angles revealed that the maximum peak wind force coefficient increased as the radius of the vortex generated by the flow separation from the windward edge of signboard became smaller. An empirical formula predicting the maximum peak wind force coefficients is derived as a function of the aspect ratios of the building and signboard, the installation position of the signboard on the building's roof, and the relative size of the signboard to the building. The accuracy of this formula is within ±20% of the experimental values.
