A novel systematic method to estimate the contact parameters of particles in discrete element simulations of soil

Abstract

Recent advances in simulation of granular matter and computation hardware let the discrete element method (DEM) evolve into the field of dynamic simulation of soils, enabling to simulate physical effects of soil deformation at particle interaction-scale. However, DEM is still lacking a generally accepted method to determine material-specific but application-independent particle contact parameters. In this article a novel, systematic method to directly determine the contact parameters of the particles is proposed. These parameters are divided into two groups: 1) independent parameters whose values are measurable, real soil properties and 2) dependent parameters whose values are set according to sufficient, modeling-intrinsic requirements. With the proposed parameter estimation strategy, the number of parameters which actually need to be chosen by lookup tables has been decreased to one single parameter. Additionally, the look-up table is only computed once and reused for every new type of soil. Thus the method is time efficient and does not repeatedly need preliminary calibration simulations and the time required to develop a mature and valid model is drastically reduced. In the article the parameter setting method is validated for a quartz sand, used to simulate the impact-driven penetration of the HP3-Mole and its corresponding experimental measurements.