| Motivated by the problem of aircraft and space-shuttle landing on an underlying unpaved soil surface in an emergency, a time-dependent mathematical formulation of high-speed wheel mobility on soil is developed and solved by a control-volume-based finite element method. The wheel-soil contact forces are determined solely on the basis of the physics of the problem. Thus, none of the usual assumptions or simplifications regarding the distribution of interfacial normal and/or shear stresses, albeit in the context of quasi-static wheel mobility, is made. The formulation allows for the incorporation of arbitrary soil constitutive equations, hence strain-rate effects. Soil and wheel inertia are fully accounted for. Consideration is given to the possible existence of a stick-slip phenomenon along the wheel-soil interface.;An object-oriented dynamic wheel-soil interaction C++ computer program is developed and validated. Predictions of soil drag and associated wheel sinkage during simulated aircraft landings are presented. The use of object-oriented programming allows for an easily re-usable and extendable code. Thus the code developed herein can readily be specialized or generalized to solve other practical soil-structure interaction problems. |
