A Numerical Model of the Ride Dynamics of a Vehicle Using a Segmented Tire Concept
Abstract
The purpose of this study was to develop and validate a digital computer simulation of the ride dynamics, including bounce, pitch, and roll, of a general single-hull, solid-axle vehicle with an arbitrary number of axles. The study also included an effort to minimize the execution time and thus the cost of the simulation by providing automatic determination of the optimum numerical integration interval to be used at each point in the simulation. The vehicle was defined as a rigid body connected to rigid axles by springs and viscous dampers. Tires were described as clusters of radially projecting springs being deflected by a nonyielding riding surface. The suspension springs and dampers were described by force-deflection and force-rate tables, thus allowing nonlinear characteristics to be handled by a piece-wise linear representation with linear interpolation between the points. The numerical integration method used was the Runge-Kutta-Merson method, which is a fourth-order method. The method requires five derivative evaluations per integration and provides an estimate of the truncation error that can be used for automatic interval adjustment. Field tests of a representative vehicle traversing a single obstacle at three different speeds and a cross-country terrain at one speed were simulated. Graphs are presented comparing simulated vehicle responses with field test data provided by the Waterways Experiment Station. The effects of integration step-size on simulated vehicle responses are illustrated with graphs comparing simulated vehicles responses using several different integration intervals. A discussion of criteria for automatic management of the integration interval is presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1973
- Accession Number
- AD0913281
Entities
People
- Windell F. Ingram