Doctor of Philosophy
Civil and Environmental Engineering
Kopp, Gregory A.
This study focused on assessing the performance of single-ply metal roofing system under high wind loads. Full-scale measurements were conducted at Insurance Research Lab for Better Homes at the University of Western Ontario, on a full-scale standing seam metal roof (SSMR) system in order to investigate the load sharing among the clip fasteners. A pressure loading approach was used for applying pressure distributions with spatial and time variation on the roof system as the induced loads on the clips were measured using installed load cells. The influence functions of clip reactions were measured. It was observed that the area of two adjacent panels all along the standing seam could be considered as the influenced surface for the clips. By integration of measured influence functions over the influenced surface, the effective areas of clips were determined. By comparing the measured effective areas with geometric tributary areas, it was shown that geometric tributary areas underestimate the amount of the load that is transferred to the edges of the roof. This underestimation is critical on the eave end at the corner of the roof. It was also observed that, as the panels deform permanently under higher wind pressures, the induced load redistributes along the standing seam and more load transfers to the eave end of the roof. This change indicates the different performances of eave and gable ends of the roof and the role of the standing seams in load sharing on the SSMR system. An analytical model was introduced to calculate the effective areas of installed clips on a standing seam metal roof, and it was shown that the performance of the clips could be modeled as vertical springs. Although the proposed analytical model only represents the linear behaviour of the roofing system, it can be used to include the influence of boundary conditions in the standard test protocols to provide more accurate load capacity.
Nasiri, Mahshid, "Full-scale measurements to evaluate single-ply metal roof performance under extreme wind loads" (2019). Electronic Thesis and Dissertation Repository. 6112.