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Abstract

Since the delayed fracture of glass was first reported, a lot of studies have been conducted. In general, it has been understood that the true character of delayed fracture behavior exists in the stress corrosion cracking process in humid environment. The process of delayed fracture in glass, however, has not been made clear sufficiently.One of the reasons for this situation is that delayed fracture characteristics depend extremely upon the defect statistics.On the other hand, when the strength of brittle materials such as glass or ceramics is examined, it is necessary to eliminate the effect of distributed Griffith cracks on strength characteristics. For this purpose, many kinds of testing methods using abraded specimens have been proposed. One of these testing methods utilizes Vickers diamond indented specimens, which may also be employed for the evaluation of delayed fracture characteristics of glass.In this paper, four points bending delayed fracture tests in deionized water were conducted by using the soda-lime-silica glass plate specimens with the initial crack and indentation pit by Vickers diamond indentation.The results show that the lateral crack morphology is a governing factor for the delayed fracture characteristics of the specimens used in this experiment.This fact is brought about by the crack propagation behavior that the initiated crack (radial crack) propagates around the lateral crack.