Fragmentation of explosively metastable glass

Abstract

An unusual form of glass with bulbous head and thin tail, known as Rupert's drops, can withstand high impact or pressure applied to the head, but explodes instantly into small particles when the tail is broken. The mechanism is not well understood. To examine this, we performed macro- and microstatistical analyses of a sample of 500 g of fragments of exploded Rupert's drops to determine the mass and particle distributions and associated fractal dimensions. To our knowledge, this is the first such statistical study of the fragmentation of a metastable material with large internal energy. The resulting fractal dimension D = 1.06 ± 0.09, derived from the scaling region of the mass and particle distribution functions approximated by power laws, differs from fractal dimensions (usually ⩾2) previously reported for many brittle materials. The observed distribution functions place constraints on proposed mechanisms for the explosive disintegration of the drops and presumably other physical systems characterized by high compressive stress at the surface and tensile stress within the core.

Ball Impact Response of Unstrengthened and Chemically Strengthened Glass Bars

“…A novel feature of the dynamic fracture of strengthened glasses is the notion of internally fueled, self‐sustained fracture fronts. Currently, limited studies have provided an in situ observation of self‐sustained failure in thermally tempered glasses in the form of glass blocks or tear drop‐shaped glass (called Prince Rupert's drops) . These thermally tempered glasses contain parabolic stress profiles marked by moderate surface compression (several hundred megapascals) with interior balancing tension of approximately half the value of the surface compression.…”

“…Currently, limited studies have provided an in situ observation of self-sustained failure in thermally tempered glasses in the form of glass blocks 23,25 or tear dropshaped glass (called Prince Rupert's drops). [26][27][28] These thermally tempered glasses contain parabolic stress profiles marked by moderate surface compression (several hundred megapascals) with interior balancing tension of approximately half the value of the surface compression. This study will extend these direct observations to chemically strengthened glasses which have steep compressive stress profiles with ultrahigh surface compression (~1 GPa on the surface) and nearconstant, low interior balancing tension (tens of megapascals).…”

Brittle fracture in a periodic structure with internal potential energy. Spontaneous crack propagation

“…So, the spontaneous failure wave can propagate in the form of a pure bridged, partially bridged or fully open crack depending on the internal energy level.Note that in some respects, the problem is related to that for the bridge crack (Mishuris et al, 2008(Mishuris et al, , 2009, to the weak-bond fracture of a lattice (Slepyan and Ayzenberg-Stepanenko, 2002), and to the transition waves in bistable structures (Slepyan and Troyankina (1984), Slepyan (2002), Slepyan et al (2005), Vainchtein (2010)). In a sense, the spontaneous crack propagation considered below also relates to the so called Prince Rupert's drop phenomenon of disintegration known from 17th century (see, e.g., Johnson and Chandrasekar, 1992) and to the fragmentation of metastable glass (Silverman et al, 2012). These phenomena can be referred to the internal potential energy, which releases under a local breakage, resulting in the spontaneous disintegration.The state of the considered structure is characterised by the following values.…”

Numerical Procedures for Calculating the Probabilities of Recurrent Runs

“…Experimental situations calling for preferential usage of a cumulative probability distribution over a probability function abound in the physical sciences, as, for example, in the analysis of fragmentation [10] and other stochastic processes leading to a power-law distribution.…”