Atomistic study of the interaction between a microcrack and a hard inclusion inβ−SiC

Abstract

We present an atomistic investigation on mechanical loading effects in a model fiber-reinforced $\ensuremath{\beta}\text{\ensuremath{-}}\mathrm{Si}\mathrm{C}$ monocrystal where a crack is present. Our simulations are both consistent with the basic results of elementary continuum mechanics and provide a deeper physical insight at the nanoscale. In particular, we propose an effective renormalization of some basic quantity (e.g., the crack length), which reconcile continuum theory to atomistics. Finally, we prove that the interaction between the microcrack and the hard inclusion (fiber) is able to increase the strength of the $\ensuremath{\beta}\text{\ensuremath{-}}\mathrm{Si}\mathrm{C}$ lattice and falls beyond the linear regime. We consistently provide a corresponding constitutive equation for the total stress field for an interacting crack-fiber pair.