Note: [] The Japanese version of this paper has been published in the Journal of the Japanese Society for Strength and Fracture of Materials, 54 (2020), 21–30.
Abstract: High speed photography by Caustics method using Cranz-Schardin camera was studied for crack propagation and divergence in thermally tempered glass. Tempered 10 mm thick glass plates were used as a specimen. Two types of bifurcation and branching as the crack divergence could be observed and clarified even in 10 mm thick tempered glass. The difference of the shadow spot sizes between bifurcation type and branching type could be confirmed.
Keywords: Crack propagation and divergence, bifurcation and branching, crack divergence energy, Caustics method, 10 mm thick tempered glass