A detailed multi-body model for dynamic simulation of off-road tracked vehicles

Currently available models for dynamic simulation of tracked vehicles usually include super-elements to describe the tracks and the suspension systems. In these models, the dynamics of the track, the interaction between each track link and the ground, and their effect on the vehicle dynamics cannot be considered properly. The rapid increase in computing speed enables the utilization of more complex models, including numerous bodies and force elements. A three-dimensional multi-body simulation model for simulating the dynamic behavior of tracked off-road vehicles was developed using the LMS-DADS simulation program. The model incorporates detailed description of the track, the suspension system, and the dynamic interaction between its components. The bodies of the model are the chassis, the wheel-arms, the wheels, and each track link. Three-dimensional contact force elements are used to describe the interaction of the track links with the vehicle's road wheels, sprocket, and idler. Additional force elements are used to simulate the bump stops and the dampers. User-defined force elements are used to describe the interaction between each track link and the ground. The normal and tangential forces are calculated using classical soil mechanics equations, such as Bekker and Janosi correlations. Sinkage and slip are calculated separately for each track link. Alternative correlations, based on recent studies of the dynamic variations of these forces, can also be used. The model was first applied to the M113 armored carrier. Simulation results under various road conditions were compared with the results of a super-element-based model. It was concluded that the influence of the track dynamics and the soil-link interaction on the vehicle dynamics can be better predicted with the newly developed model. (C) 2004 ISTVS. Published by Elsevier Ltd. All rights reserved.