The Discrete Element Method (DEM) is useful for modelling granular flow. The accuracy of DEM modelling is dependent upon the
model parameter values used. Determining these values remains one of the main challenges. In this study a method for determining the
parameters of cohesionless granular material is presented. The particle size and density were directly measured and modelled. The particle
shapes were modelled using two to four spheres clumped together. The remaining unknown parameter values were determined using
confined compression tests and angle of repose tests. This was done by conducting laboratory experiments followed by equivalent numerical
experiments and iteratively changing the parameters until the laboratory results were replicated. The modelling results of the confined
compression tests were mainly influenced by the particle stiffness. The modelling results of the angle of repose tests were dependent
on both the particle stiffness and the particle friction coefficient. From these observations, the confined compression test could be used to
determine the particle stiffness and with the stiffness known, the angle of repose test could be used to determine the particle friction coefficient.
Usually DEM codes do not solve the equations of motion for so-called walls (non-granular structural elements). However, in this
study a dynamic model of a dragline bucket is developed and implemented in a commercial DEM code which allows the dynamics of the
walls to be modelled. The DEM modelling of large systems of particles is still a challenge and procedures to simplify and speed up the
modelling of dragline bucket filling are presented. Using the calibrated parameters, numerical results of bucket filling are compared to
experimental results. The model accurately predicted the orientation of the bucket. The model also accurately predicted the drag force
over the first third of the drag, but predicted drag forces too high for the subsequent part of the drag.
کالیبراسیون پارامترهای روش المان گسسته و شبیه سازی عملیات پر کردن باکت معدن (مقاله 12 به زبان انگلیسی)
