Investigating a wind tunnel method for determining wind-induced loads on roofing tiles: Fid-Bau Portal

Investigating a wind tunnel method for determining wind-induced loads on roofing tiles

Smith, Daniel J. / Masters, Forrest J. / Chowdhury, Arindam G.

Abstract Current design loads for roofing tile systems in the U.S. are determined based on a standardized wind tunnel testing method developed in the 1990s to examine wind-induced pressures on the upper and lower surfaces of the tile. The method neglects several key parameters that are well known to affect wind loading (e.g. wind angle, specimen shape, etc.). The research objective of this study is to investigate this method by [1] characterizing wind-induced surface pressure distributions on field tiles for varying wind angles of attack and [2] measuring load path intensity through mechanically fastened tile attachments. Surface pressure distributions were measured on three full-size, rapid prototyped roofing tile models with 256 pressure taps immersed in wind flows. The models are geometrically identical to low-, medium- and high-profile concrete roofing tiles that are widely used in high wind areas. Additionally, their real counterparts were instrumented with load cells to measure reaction forces at mechanical fasteners. The results highlight areas of the method that are lacking in specificity and shows that low-resolution pressure measurement may yield conservative parameters for low- and medium-profile tiles but is potentially not conservative for asymmetric (s-shaped) high-profile tiles.

Highlights • Historical basis of the wind testing standard for roofing tiles in the US is briefly reviewed. • Aerodynamics of roofing tiles are investigated using the standardized method. • Wind-induced surface pressures and fastener reactions are measured. • The analysis discusses key limitations in the methodology.