An Einstein Model of Brittle Crack Propagation
arXiv:cond-mat/9611107 · doi:10.1103/PhysRevLett.78.78
Abstract
We propose a minimal nonlinear model of brittle crack propagation by considering only the motion of the crack-tip atom. The model captures many essential features of steady-state crack velocity and is in excellent quantitative agreement with many-body dynamical simulations. The model exhibits lattice-trapping. For loads just above this, the crack velocity rises sharply, reaching a limiting value well below that predicted by elastic continuum theory. We trace the origin of the low limiting velocity to the anharmonicity of the potential well experienced by the crack-tip atom.
To appear in Physical Review Letters, 9 pages, self-contained TeX file, email to [email protected] or [email protected] for two postscript figures