Possibility of Supervelocity of Glass Fracture

Abstract

Extrapolating the Glathart-Preston equation for the variation of the glass strength with the loading time, it is assumed that, before a fracture is caused in soda-lime glass within the order of microseconds, the stress applied on it must have attained a value extraordinarily higher than the one for usual impacts—the difference in magnitude being nearly one order. From this assumption it is suggested that the local compression strain in soda-lime glass when subjected to impact by underwater sparks must surpass the ordinary linear elastic limit and accordingly that there may be a possibility of propagation of this fracture at a velocity higher than the normal limit.