Cracking Resistance of Glass in Terms of the Principles of Fracture Mechanics

The basic principles of subcritical crack growth (SCG) are developed based on linear elastic fracture mechanics (LEFM) and dynamic crack growth (DCG), within the framework of linear elastic dynamic fracture mechanics (LEDFM), in order to determine the criteria of fracture toughness and crack branching (bifurcation, forking) in glass. The fractographic analysis of fracture surfaces of the samples tested for bend tensile is used for determining the required calculation parameters. The results of the experimental studies are analyzed with the use of a probabilistic-statistical method for estimating the data with the use of two-parameter Weibull distribution. The critical stress intensity factor is taken as a fracture toughness criterion. The crack branching stress intensity factor is used as a crack branching criterion. These values are determined using the quantile function of the assumed distribution for a 95% reliability level, at the lower limit of the 95% confidence interval.