The numerical modelling of excavator bucket filling using DEM

The filling of an excavator bucket is a complex granular flow problem. In order to optimize the filling process, it is important to understand the different mechanisms involved. The discrete element method (DEM) is a promising approach to model soil-implement interactions and it was used in this study to model the filling process of an excavator bucket. Model validation was based on the accuracy with which the model predicted the bucket drag force and the development of the different flow regions. Compared to experimental measurements, DEM predicted lower bucket drag forces, but the general trend was accurately modelled. At the end of the filling process the error in predicted drag force was 20%. Qualitatively, there was a good agreement between the observed and the modelled flow regions in terms of position and transition from one stage to the other. During all stages of filling, DEM was able to predict the volume of material inside the bucket accurately to within ±6%.