Mixed mode fracture in soda lime glass analyzed by using the generalized MTS criterion

Glasses are known to be vulnerable to tensile stresses particularly in the presence of pre-existing cracks. Since cracks in glass components are very often subjected to mixed mode loading, several researchers have studied mixed mode fracture in soda lime glass using different test specimens. Among these specimens, the cracked Brazilian disc specimen has been used most frequently by investigators. However, it is shown in this paper that the previously reported experimental results obtained from the cracked Brazilian disc specimen for several glasses are always underestimated by fracture theories like the maximum tangential stress criterion. A generalized maximum tangential stress criterion is then employed for predicting the mixed mode fracture test results. It is shown that the experimental results obtained from the cracked Brazilian disc specimen and reported in the literature for soda lime glass can be estimated very well when the generalized criterion is used. It is also shown that the same criterion can be used for predicting the test results available in the literature for brittle fracture in a glass plate containing an angled center-crack.