Theoretical estimation of the drawbar pull for two-axle automotive vehicles

Abstract

The drawbar pull, defined as the amount of force available to an automotive vehicle at the drawbar for pulling or accelerating a load, represents an important characteristic used to define its traction performances. Because the experiments necessary to determine that force are relatively difficult and expensive to realize, a theoretical assessment of that characteristic may be extremely useful to identify the traction potential of the studied vehicle. This paper presents an algorithm able to approximate the realizable drawbar force of an automotive vehicle when it moves on different types of ground. For the computation, the ground characteristics may be adopted from the literature, while the necessary input data of the vehicle is normally given by the manufacturers or can be relatively easily obtained by measurements. The algorithm can be very useful in the primary stages of vehicle design. The paper also presents some influences of the constructive data and driving conditions on the drawbar force magnitude.