# THEORETICAL MODEL FOR EVALUATION OF TRACTIVE PERFORMANCE OF FORESTRY MACHINE’S WHEEL

V. Ivanov, M. Stepanishcheva, E. Khitrov, D. Iliushenko
Thursday 11 October 2018

ABSTRACT

The paper suggests a mathematical model, which is to evaluate interaction of a wheeled mover and forest soil. The model is composed by compiling results, which were obtained by independent researchers in the framework of vehicle locomotion theory under off-road conditions and authors` obtained dependencies. In particular, the model includes refined formula for calculating shape of contact area with the ground (formula allows to take into account the deformation modulus effect on contact area shape), for calculating mover’s radial deformation (formula allows to take into account the tire inner pressure, mover geometry, soil and mover deformation consistency), for accounting time of ground stress (the formula is to assess the impact of wheel speed on ground deformation), for assessing soil shear strain. The article describes calculating procedure for the proposed model and gives examples of calculation results (estimate rolling resistance coefficient, thrust coefficient, drawbar pull coefficient for given values of mover’s diameter, width, inner tire pressure, speed, rut depth and adjusted wheel load). The results establish non-linear relationships between rolling resistance coefficient, the net thrust coefficient and the drawbar pull coefficient and the inputs. The paper also provides simplified mathematical models for engineering calculations of rolling resistance (depending on the deformation modulus, tire width, wheel diameter, adjusted wheel load and the inner pressure in the tire), net thrust coefficient (depending on the soil deformation modulus, tire width and the slip ratio) and the drawbar pull coefficient (depending on the deformation modulus, tire width, wheel diameter, adjusted wheel load, inner pressure in the tire and the slip ratio). These models come as results of computational experiment with proposed formulae sets.

Keywords: rolling resistance coefficient, net thrust coefficient, drawbar pull coefficient, wheeled mover

Home | Contact | Site Map | Site statistics | Visitors : 0 / 353063

© Copyright 2001 International Multidisciplinary Scientific GeoConference & EXPO SGEM. All Rights Reserved.