Size effect in heterogeneous materials analyzed through a lattice discrete element method approach

•Carpinteri’s brittleness allows to identify specimen ductile-brittle global behavior.•Several experimental and numerical uniaxial tensile tests are done to verify the brittle number classification.•The use of this version of Lattice Element Method allows capturing the damage process in quasi-brittle materials.•This version of Lattice Element Method uses the brittleness number to calibrate the input parameters. In the Lattice Discrete Element Method (LDEM), different types of mass are considered to be lumped at nodal points and linked by means of one-dimensional elements with arbitrary constitutive relations. In previous studies on the tensile fracture behavior of rock samples, it was verified that numerical predictions of fracture of non-homogeneous materials using LDEM models are feasible and yield results that are consistent with the experimental evidence available so far. In the present paper, a discussion of the results obtained with the LDEM is presented. A set of rock specimens of different sizes, subjected to monotonically increasing simple tensions, are simulated with LDEM. The results were analyzed from the perspective of the brittleness number, proposed by Alberto Carpinteri, to measure the brittleness level of the structure under study. The satisfactory correlation between the experimental results and LDEM results confirms the robustness of this method as a numerical tool to model fracture processes in quasi-brittle materials.