On the extraordinary strength of Prince Rupert's drops

Abstract

Prince Rupert's drops (PRDs), also known as Batavian tears, have been in existence since the early 17th century. They are made of a silicate glass of a high thermal expansion coefficient and have the shape of a tadpole. Typically, the diameter of the head of a PRD is in the range of 5-15 mm and that of the tail is 0.5 to 3.0 mm. PRDs have exceptional strength properties: the head of a PRD can withstand impact with a small hammer, or compression between tungsten carbide platens to high loads of $15 000 N, but the tail can be broken with just finger pressure leading to catastrophic disintegration of the PRD. We show here that the high strength of a PRD comes from large surface compressive stresses in the range of 400-700 MPa, determined using techniques of integrated photoelasticity. The surface compressive stresses can suppress Hertzian cone cracking during impact with a small hammer or compression between platens. Finally, it is argued that when the compressive force on a PRD is very high, plasticity in the PRD occurs, which leads to its eventual destruction with increasing load. Published by AIP Publishing.

Explosive fragmentation of Prince Rupert’s drops leads to well-defined fragment sizes

“…The rapid cooling causes thermal contraction, and the fact that the outside of the drop cools before the inside then leads to very large tensile stresses in the droplet center and compressive stresses on the exterior. The very large compressive forces suppress crack growth, giving rise to the drop’s extreme strength: they do not break when hit with a hammer; in controlled experiments, Prince Rupert’s drops can withstand loads of more than 10 kN without breaking 27 . If, however, a crack is initiated and it is able to reach the tensile central region, by e.g.…”

“…We study here the fragmentation of a remarkably strong, yet explosively disintegrating piece of glass, the Prince Rupert’s drop (also known as “Dutch tears”) 25 – 27 . Unlike the studies mentioned above, we find that Prince Rupert’s drops undergo a self-sustained fragmentation process driven by internal stresses only.…”

Determination of the full deformation tensor by multi-Bragg fast scanning nano X-ray diffraction

“…However, they can play a critical role in determining the material properties, allowing for often surprising changes to them. The most well known example must be Prince Rupert's drops (Aben et al, 2016), and also the properties of semiconductors, such as Si, SiGe and Ge (Lee et al, 2005). In particular, phase-change materials, such as the VO 2 (Liu et al, 2011) investigated here, can be significantly altered by external or internal stresses leading to strain.…”

Experimental Evaluation and Numerical Modelling Residual Stresses in Glass Panel

“…In the current study an attempt is made to combine the know-how and capabilities of the private company GlasStress Ltd in area of experimental study of residual stresses in glass structures [10][11][12] and optimization workgroup of TTU (Tallinn University of Technology) in area of structural analysis and design optimization [13][14][15][16][17].…”