Wind tunnel tests and equivalent 1-minute loads for the design of cladding glass

Abstract Three methods for converting fluctuating wind loads to equivalent 1-minute constant loads have been proposed in the literature: (1) a simplified method that assumes a linear load-stress relationship and, in addition, that the glass strength is affected only by the peak wind pressure rather than by the whole time history of the load, (2) a simplified method applicable to annealed glass that assumes a linear load-stress relationship, and (3) a method based on fracture mechanics models and nonlinear stress analysis, developed at the National Bureau of Standards. This paper compares the three methods for estimating equivalent 1-minute wind loads and examines the effect on the estimates of assuming different distribution parameters of glass strength and different fracture mechanics parameters. The results suggest that the second of the above methods is adequate in most cases but that the first method yields equivalent 1-minute loads that are too low by about 20 percent for annealed glass and about 15 percent for heat strengthened glass.