Experimental validation of a differential variational inequality-based approach for handling friction and contact in vehiclegranular-terrain interaction.pdfVIP

Available online at ScienceDirect Journal of Terramechanics 65 (2016) 1–13 Journal of Terramechanics /locate/jterra Experimental validation of a di?erential variational inequality-based approach for handling friction and contact in vehicle/granular-terrain interaction Daniel Melanz a,b,?, Paramsothy Jayakumar a, Dan Negrut b a U.S. Army Tank Automotive Research Development and Engineering Center, Warren, MI 48397-5000, USA b Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706-1572, USA Received 15 October 2015; accepted 28 January 2016 Available online 31 March 2016 Abstract The observation motivating this contribution was a perceived lack of expeditious deformable terrain models that can match in mobility analysis studies the level of ?delity delivered by today’s vehicle models. Typically, the deformable terrain-tire interaction has been modeled using Finite Element Method (FEM), which continues to require prohibitively long analysis times owing to the complexity of soil behavior. Recent attempts to model deformable terrain have resorted to the use of the Discrete Element Method (DEM) to capture the soil’s complex interaction with a wheeled vehicle. We assess herein a DEM approach that employs a complementarity condition to enforce non-penetration between colliding rigid bodies that make up the deformable terrain. To this end, we consider three standard terramechanics experiments: direct shear, pressure-sinkage, and single-wheel tests. We report on the validation of the complementarity form of contact dynamics with friction, assess the potential of the DEM-based exploration of fundamental phenomena in terramechanics, and identify numerical solution challenges associated with solving large-scale, quadratic optimization problems with conic constraints. Published by Elsevier Ltd. on behalf of ISTVS. Keywords: Terramechanics; Discrete element method; Friction and contact; Di?erential variational inequality; Validation; Calibration;