Brazilian test - a microscopic point of view on tensile fracture generation

Abstract

The tensile strength of solid materials is one of the most important parameter describing a behavior of the material under external mechanical loading and thus its knowledge is of great practical importance. However, the direct measurement of tensile strength especially for brittle materials is quite difficult and only limited results are available. To cope with this situation various methods of indirect measurements have been proposed among others the, so called Brazilian test is the most popular. The method relies on diametrically loading of disc-like sample of the brittle material until it splits apart due to a induced tensile stress. In this paper we report our effort of describing the fracturing process during the Brazilian test from the “microscopic”point of view. For this purpose we use an advanced implementation of the Discrete Element Method - the ESySParticle software. We represent rock specimen as a set of interacting spherical particles which mimic grains of real rock material. We have observed that the maximum loading force which sample can withstand almost linearly scales up with a ratio of maximum-tominimum particles diameters.