New calibration of partial material factors for the structural design of float glass. Comparison of bounded and unbounded statistics for glass strength

Partial material factors need to be calibrated to guarantee the target failure probability of glass structures according to the semi-probabilistic (level I) methods of design. Calibration is made by comparison with results obtainable with the full probabilistic approach (level III) on paradigmatic case studies. Considering the results of previous work that assessed the validity of various statistical models of glass strength, we use a generalized distribution of the Weibull type to derive new partial factors that account for a lower bound for glass strength or not. The partial factors so calculated are much lower than those previously obtained from the classical two-parameter Weibull distribution, and are in agreement with the coefficients commonly used in practice. Moreover, the variation of the partial factors with respect to changes in failure probability is similar to what is applied to other building materials.