Simulación atomística de la fractura dinámica en un material frágil

Abstract

In this work molecular dynamics simulations (MD) of a model of uniaxial tension at were made rates of deformation ($\dot\varepsilon \approx$ $3.9\times 10^{11}{\mathrm { s}}^{ - 1}$), that allowed the generation and the characterization of the dynamic fracture in a previously cracked ideal brittle nanomaterial (silicon). These simulations generated crack propagation at an average velocity of $\approx 2$ km/s with characteristics similar to those observed in experiments at the macroscopic scale, in other simulations (and theory). Some of these similarities were the brittle propagation in the cleavage planes (110) and (111), the influence of the stress tensor in the crack path, average and instantaneous values of the crack speed and the morphology of the simulated samples; this last qualitative similarity with the fracture surfaces obtained in experiments on a macroscopic scale evokes the concept of self-affinity of the surfaces.