A finite element analysis of pneumatic‐tire/sand interactions during off‐road vehicle travel

Abstract

Purpose -The purpose of this paper is to carry out a series of transient, non-linear dynamics finite element analyses in order to investigate the interactions between a stereotypical pneumatic tire and sand during off-road vehicle travel. Design/methodology/approach -The interactions were considered under different combined conditions of the longitudinal and lateral slip as encountered during "brake-and-turn" and "drive-and-turn" vehicle maneuvers. Different components of the pneumatic tire were modeled using elastic, hyper-and visco-elastic material models (with rebar reinforcements), while sand was modeled using the CU-ARL sand models developed by Grujicic et al. The analyses were used to obtain functional relations between the wheel vertical load, wheel sinkage, tire deflection, (gross) traction, motion resistance and the (net) drawbar pull. These relations were next combined with Pacejka magic formula for a pneumatic tire/non-deformable road interaction to construct a tire/sand interaction model suitable for use in multi-body dynamics analysis of the off-road vehicle performance. Findings -To rationalize the observed traction and motion resistance relations, a close examination of the distribution of the normal and shear contact stresses within the tire/sand contact patch is carried out and the results were found to be consistent with the experimental counter parts. Originality/value -The paper offers insights into the interactions between a stereotypical pneumatic tire and sand during off-road vehicle travel.

Helically-driven granular mobility and gravity-variant scaling relations

“…There is a long-standing interest to better understand mobility in granular environments within both the robotics and granular physics communities. [1][2][3][4][5][6][7][8][9] This is important for new mobility and material transfer solutions, particularly in the space sector where increased mass and volume are oen costly while increased moving parts or complexity are regarded as increasing risk. This complexity is further compounded by the variety of granular materials which exist.…”

The effect of up‐armoring of the high‐mobility multi‐purpose wheeled vehicle (HMMWV) on the off‐road vehicle performance

“…Compaction (Grujicic et al, 2008a(Grujicic et al, , b, 2009(Grujicic et al, , 2010 Compaction (Grujicic et al, 2008a(Grujicic et al, , b, 2009(Grujicic et al, , 2010 Hydro (Grujicic et al, 2008a(Grujicic et al, , b, 2009(Grujicic et al, , 2010 Geometrical instantaneous strain Table II.…”

“…The tire/sand non-linear force-element model (Grujicic et al, 2010) was implemented as a "utyre_spck.f" user tire-model subroutine in Simpack (Intec, 2008). Within this subroutine, the current values of the wheel-center kinematic parameters (e.g.…”

“…In the case of off‐road vehicle performance analysis, the availability of high‐fidelity robust models for the tire/soil interaction force elements is particularly critical. In our recent work (Grujicic et al , 2008a, b, 2009, 2010), finite element simulations of tire/sand interactions under different conditions of inflation pressure, vertical load, friction coefficient, longitudinal slip, and slip angle were used to formulate and parameterize a tire/soil interaction force element for the case of the Goodyear Wrangler HT LT 235/H5 R15 tire and prototypical dry sand. Limited experimental data were then used to validate the model.…”

Three-dimensional finite element and analytical modelling of tyre–soil interaction

“…An additional sticking stiffness was applied inside the sticking region by default in Abaqus. Xia 33 and Grujicic 38 reported that a constant coefficient of friction could be used for the tyre-soil contact. The coefficient of friction was assumed as 0.6 for the tread-soil contact in this article.…”