New universality class for the fragmentation of plastic materials

TL;DR

This study uncovers a new universality class in the fragmentation of polymeric materials, characterized by a distinct power law exponent, driven by shear-dominated crack formation and plastic deformation.

Contribution

The paper introduces a novel universality class for polymer fragmentation, supported by experimental data and a discrete element model emphasizing shear and plasticity effects.

Findings

Power law mass distribution with exponent ~1.2

Distinct from bulk material fragmentation exponents

Model reproduces experimental fragmentation behavior

Abstract

We present an experimental and theoretical study of the fragmentation of polymeric materials by impacting polypropylene particles of spherical shape against a hard wall. Experiments reveal a power law mass distribution of fragments with an exponent close to 1.2, which is significantly different from the known exponents of three-dimensional bulk materials. A 3D discrete element model is introduced which reproduces both the large permanent deformation of the polymer during impact, and the novel value of the mass distribution exponent. We demonstrate that the dominance of shear in the crack formation and the plastic response of the material are the key features which give rise to the emergence of the novel universality class of fragmentation phenomena.