ANALYSIS OF 3TEERABILITY OF TRACKED VEHICLES; THEORETICAL PREDICTIONS VERSUS FIELD MEASUREMENTS

摘要

A mathematical model has been developed for predicting the steering performance of high-mobility/agility tracked vehicles in environments ranging from very soft soils - to hard surfaces such as rigid pavements. The tractive forces between the terrain and the vehicle track are simulated by a rheological model that accounts for nonlinear shear-stress/shear-deformation behavior, the effect of deformation rate on shearing resistance, and the effect of pressure on shear resistance and plastic yielding. The rheological model is coupled with the kinematics and the characteristics of the vehicle to develop the general equations governing the transient as well as the steady-state turning motion of a vehicle on a level, flat surface. A computer program, named AGIL, numerically integrates and solves these equations of motion in terms of the kinematics of the problem. The model is partially validated by comparing field measurements from a series of steering tests conducted in the vicinity of Vicksburg, Mississippi, with the corresponding model predictions.