A detailed single-link track model for multi-body dynamic simulation of crawlers

Currently available models for dynamic simulation of tracked vehicles do not include the necessary detail required of a high-fidelity model of crawlers. The rapid increase in computing speed enables the utilization of more complex models, which may include many bodies and force elements. A three-dimensional multi-body simulation model for simulating the dynamic behavior of a crawler was developed using the LMS-DADS simulation program. The model incorporates detailed description of the track, the suspension system, and the dynamic interaction among its components. Three-dimensional contact force elements are used to describe the interaction of the track links with the vehicle's rollers, sprocket, and idler. User-defined force elements are used to describe the interaction between each track link and the soil. The normal and tangential forces are calculated using classic soil mechanics equations, such as Bekker and Janosi correlations. The grousers, which are a significant part of any crawler track link, were modeled using McKeys' approach. The model includes new elements, such as the plasticity and viscosity properties of the soil. Sinkage and slip are calculated separately for each track link. Simulation results were compared with the experimental results. In some ride conditions, the simulation results indicate forward motion of a track link while in contact with the soil. The existing theories consider backward motion of a track link when the vehicle moves forward and the link is in contact with the soil. This phenomenon was verified in the experimental work. 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.