Wind Tunnel and Uniform Pressure Tests of a Standing Seam Metal Roof Model

Abstract

A simplified model of a standing seam metal roof was tested to failure under both uniform and wind tunnel pressures. The model was designed to fail at clips that were calibrated to a scaled strength based on full-scale testing performed at Mississippi State University. The goal of the study was to quantify the relationship between uniform uplift pressure used in standard test procedures and the dynamic pressures that occur during real wind loading that cause failure. An effective external pressure coefficient was formed based on the uniform pressure and mean roof height wind speed that were required to fail the model. This coefficient was compared with GCP values suggested by ASCE 7-02. The model indicated that, for a component designed for the corner zone, the ASCE specified design pressures would overestimate the pressures that would be effective in failing a clip by 30%. Comparison between clip load response and the pressures measured on a rigid model demonstrated that the response was closely related to the integrated pressures surrounding the clip using appropriate influence functions.