By means of atomistic simulations, we investigate the failure strength in plane strain conditions of a brittle solid containing nanosized stress concentrators, i.e., a straight crack, a cylindrical hole, or a spherical hole. We find that the failure strength of the defected solid strongly depends on the defect size, in contrast with the predictions of standard elasticity theory. A high strength reduction due to voids as large as few atoms is observed. Such results have been included in two analytical failure criteria, namely, the average stress criterion and the point stress criterion. Both models introduce a length scale typical of the system, tailored at describing the process zone near the nanovoids. We provide a numerical estimate for this length scale, which is found to be specific for any defect, and we reconcile atomistic results to continuum into a coherent picture.
Failure strength of brittle materials containing nanovoids
Mattoni A;Colombo L
2007
Abstract
By means of atomistic simulations, we investigate the failure strength in plane strain conditions of a brittle solid containing nanosized stress concentrators, i.e., a straight crack, a cylindrical hole, or a spherical hole. We find that the failure strength of the defected solid strongly depends on the defect size, in contrast with the predictions of standard elasticity theory. A high strength reduction due to voids as large as few atoms is observed. Such results have been included in two analytical failure criteria, namely, the average stress criterion and the point stress criterion. Both models introduce a length scale typical of the system, tailored at describing the process zone near the nanovoids. We provide a numerical estimate for this length scale, which is found to be specific for any defect, and we reconcile atomistic results to continuum into a coherent picture.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
