New model for surface fracture induced by dynamical stress

TL;DR

This paper presents a molecular dynamics model for surface fracture caused by dynamically applied isotropic stress, analyzing how stress rate, magnitude, and temperature influence fragment distribution and system stability.

Contribution

The study introduces a new model linking dynamic stress to fracture patterns, revealing invariance in fragment distribution under specific conditions and identifying a critical stress threshold for instability.

Findings

Fragment distribution depends on stress rate, magnitude, and temperature.

System becomes unstable at a critical stress value.

Fragment distribution invariance occurs at fixed temperature-to-stress change ratio.

Abstract

We introduce a model where an isotropic, dynamically-imposed stress induces fracture in a thin film. Using molecular dynamics simulations, we study how the integrated fragment distribution function depends on the rate of change and magnitude of the imposed stress, as well as on temperature. A mean-field argument shows that the system becomes unstable for a critical value of the stress. We find a striking invariance of the distribution of fragments for fixed ratio of temperature and rate of change of the stress; the interval over which this invariance holds is determined by the force fluctuations at the critical value of the stress.