Break-up of shells under explosion and impact

TL;DR

This study combines experiments and simulations to analyze how thin shells made of brittle material break under impact and explosion, revealing a phase transition and a unique universality class for shell fragmentation.

Contribution

It introduces a 3D discrete element model for shell fragmentation and demonstrates the phase transition nature of the process, differing from bulk systems.

Findings

Power law fragment size distributions observed in experiments and simulations.

Phase transition underlies the fragmentation process, with different nature for impact and explosion.

Shell fragmentation defines a distinct universality class from bulk systems.

Abstract

A theoretical and experimental study of the fragmentation of closed thin shells made of a disordered brittle material is presented. Experiments were performed on brown and white hen egg-shells under two different loading conditions: fragmentation due to an impact with a hard wall and explosion by a combustion mixture giving rise to power law fragment size distributions. For the theoretical investigations a three-dimensional discrete element model of shells is constructed. Molecular dynamics simulations of the two loading cases resulted in power law fragment mass distributions in satisfactory agreement with experiments. Based on large scale simulations we give evidence that power law distributions arise due to an underlying phase transition which proved to be abrupt and continuous for explosion and impact, respectively. Our results demonstrate that the fragmentation of closed shells defines a universality class different from that of two- and three-dimensional bulk systems.