A stochastic analysis of glass crack initiation under thermal loading

Window glass breakage plays a key role in compartment fire development as it opens a new vent for fresh air that accelerates the fire. To explore the correlation between temperature change and crack initiation, a series of experiments were preformed for float and Low-E glasses under uniform radiation conditions in a well designed facility. At the time of crack, the critical temperature differences of float glass and Low-E glass are 95 °C and 108 °C, respectively, with a same central temperature of 152 °C. The critical breaking stress occurs at 51 MPa and 70 MPa for float and Low-E glass, respectively. Detailed Weibull distribution functions on temperature and stress are obtained by fitting the experimental data. Failure probability function, survival probability function, probability density function are obtained and used to predict the glass failure with the survival probability at 0.9 and failure probability at 0.1. These results may be used to predict the crack probability of a glass bearing certain temperature and stress distributions.