Modeling and Simulation of Soil and Soil-Tool Interaction for Industrial Applications

Abstract

Modeling of soil-tool interaction for industrial applications involves the coupling of soil models, mostly based on the Discrete Element Method (DEM), with multibody systems, representing construction machinery such as excavators or wheel loaders. To obtain accurate predictions of reaction forces on tools like wheel loader buckets, it is essential to have an appropriate parametrization procedure, which makes use of data obtained from laboratory tests such as the triaxial compression test or direct shear test for different types of soil. Simulations with suitable DEM-softwares can then be validated against the experimental data to assess the applicability and performance of the numerical methods [2, 3] The DEM software GRAnular Physics Engine (GRAPE) developed at Fraunhofer ITWM in Germany has been successfully used to simulate compression and shear tests and has been proven to yield good predictions of the soil-tool interaction and draft forces [4] for spherical particles such as coarse sand. A year-long collaboration with the Fraunhofer-Chalmers Centre (FCC) in Sweden has successfully resulted in the development of a soil simulation toolbox for FCC’s general purpose DEM solver Demify® incorporating and enhancing the simulation techniques used in GRAPE [1]. Co-simulation is enabled through an FMI interface coupling Demify® with multibody systems modeled e.g., in Simulink to evaluate relevant variables such as forces at critical linkage joints of the construction machines. To model real-life application scenarios, the entire workflow must be considered, from the soil parametrization process, to setting the particulate soil model and performing numerical simulations for the specific problem, to the final post-processing to analyze the load data. We will characterize and discuss the different steps of the workflow and present simulation results obtained with the toolbox Demify® for Heavy Machinery.