Simulation of front end loader bucket-soil interaction using discrete element method

The design of earthmoving equipment requires reliable estimates of resisting forces from the soil or rock to be manipulated. A series of discrete element simulations with polyhedral particles designed to replicate a series of bucket-soil interaction experiments are presented. The experiments involve manipulation of a pile of gravel, consisting of angular and sub-rounded particles, with a prototype of a front end loader bucket. The geometry of the soil pile and the trajectory of the bucket from each experiment are simulated using discrete element method (DEM). A single set of DEM model properties, including inter-particle contact friction angle estimated from the initial configuration of the soil pile prior to the start of the experiments, are used for all simulations. The total soil reaction forces acting on the bucket in both horizontal and vertical directions are calculated from each simulation and are compared to measured forces from the corresponding experiment. The results show both qualitative and quantitative agreement between simulations with polyhedral particles and experiments with angular and sub-rounded particles. The major source of discrepancy is attributed to the large particle sizes in the simulation compared to the experiments. Using smaller particles improves the results and provides a better match with the experiments. Other sources of discrepancy are also discussed. The simulations demonstrate that DEM with polyhedral particles can be used to reliably simulate bucket-soil interaction and to estimate force feedback into earthmoving equipment. Copyright (C) 2007 John Wiley & Sons, Ltd.