Analysis of symmetric fracture mirrors in glass bottles

Abstract

A B S T R A C T Fracture conditions which defined the mirror fracture that developed from random flaws were characterized in glass bottles. A constant ratio of the mirror constant to the critical stress intensity factor (A/KIc) equal to 2.35 with a scatter of 12% was found, The sharp transition between the flaw and the mirror plane signifies an abrupt transition to rapid fracture propagation. The model implied by Shand that the mirror boundary is the loci of all points occurring at different times when conditions for bifurcation are reached, is confirmed. For this purpose both changes of stress with the thickness of glass wall and edge effects on the stress intensity factor were considered,

The index of hackle raggedness on joint fringes

“…The gap between the top value of the scale, 10, and the value of 6.8 found for joint A probably suggests that joint A was not formed by the most dynamic conditions, and that the 10 IHR value would be obtained under more extreme dynamic conditions, such as intense fracture of glass in the laboratory (e.g. Bahat et al 1982, fig. 2).…”

“…Hence, hackle formation is associated with the distinct attainments of vt by both the primary and the secondary cracks. This association, however, does not imply a dependence of hackle formation on v c It has been suggested that hackle formation is, instead, stress intensity dependent (see an extended discussion on this topic in Bahat et al 1982). This dependence is, perhaps, even more intricate than the latter, as shown below.…”

“…Kerkhof 1975) and are the 'dynamic end member' (at a velocity of -> 10 -1 m s -1 in glass: Wiederhorn (Bahat et al 1982) the origin, o, part of the primary mirror, M1, a thin rim of mist, m, at the mirror boundary, and a rim of hackle, h. Additional sequences occur three times, beginning with M2, M3 and M4, respectively (the fourth cycle is broken), Fracture branching initiates at the outer boundary of each mist or hackle rim, before the various M signs (further details have been given by Bahat et al 2004).…”

Differentiation of crack branching types in fractured glass

“…Procedure. -Ten soda-lime glass bottles having identical geometries (from a particular production line) were fractured by the same technique used by Bahat et al [13]. Briefly, the bottles were wrapped in scotch tape to prevent fragment scattering after bursting (fig.…”