Granular Matter (2017) 19:60 DOI 10.1007/s10035-017-0734-5 ORIGINAL PAPER Bond calibration method for Young’s modulus determination in the discrete element method framework Danilo Estay 1 · Felipe Chacana 1 · Jaime Ibarra 1 · Luis Pérez 1 · Sheila Lascano 1 Received: 22 August 2016 © Springer-Verlag Berlin Heidelberg 2017 Abstract A new methodology for the calibration of bond microparameters in rocks represented by a package of joined random spherical particles in the discrete element method (DEM) framework is presented. Typically, calibration is achieved through a trial-and-error procedure using several DEM simulations of uniaxial compressive tests (UCTs). The bond calibration model (BCM) does not need a time- dependent UCT-DEM simulation to establish the relation between the microproperties of the bond and the macro- properties of the rock specimen. The BCM uses matrices to describe the interaction forces exerted by bonds and, by means of an assembly process similar to the finite ele- ment method, it can describe the complex network of bonds, enabling the model to capture small variations in particle size and bond distribution as demonstrated in this work. In this work, the BCM is presented and compared with UCT simulations performed using Esys Particle software. Multi- ple simulations are done with constant bond properties and different particle size ratios ( D MAX / D MIN ) that cause small variations in the specimen’s Young’s modulus; these varia- tions are well captured by the BCM with an error of <10%. B Danilo Estay danilo.estay@usm.cl Felipe Chacana felipe.chacana@usm.cl Jaime Ibarra jaime.ibarra@alumnos.usm.cl Luis Pérez luis.perez@usm.cl Sheila Lascano sheila.lascano@usm.cl 1 Universidad Técnica Federico Santa María, Valparaiso, Chile Keywords Discrete element method · Material calibration · Microproperties/macroproperties relation 1 Introduction The discrete element method (DEM) was originally designed for the description of granular flow [3]. The model considers a finite number of particles that interact by normal and tan- gential forces. The translational and rotational positions of the particles are obtained by integration of Newton’s equation of motion. The original DEM formulation considers particles as unbreakable. Because the fracture process cannot be explic- itly represented, its application field is restricted to simulation of particle flow. In processes in which fracture is an important part of material kinematics such as in comminution pro- cesses, the classical DEM capabilities need to be extended. According to how fracture is incorporated, they can be clas- sified into two main groups: – Bonding elements: Particles are joined together by a bond element. The element has a stiffness that allows relative motion between joined particles and ultimate strength to account for element breakage. This process is similar to what occurs in concrete, in which cement is used to bond gravel [2, 7–9, 11]. – Particle breakage: This methods allows for particle subdivision. Breakage is determined according to pre- established criteria that can be based on a stress-field [4, 5] or population-based model [6]. This work focuses on bonding-element-based methods and calibration of such models. Establishing the mechanical 123