Modelling of dynamics of the suspension of tandem axles of a multi-axle vehicle provided with a novel load-equalising system

Abstract

The paper presents the problem of using multi-axle suspension systems in vehicles, concerning unbalanced distribution of axle loads while moving in off-road conditions. An innovative load balancing system for tandem axles, which limits the occurring overloads, is presented. A mathematical model is proposed to represent the suspension of a front “quarter” of a four-axle vehicle provided with a novel system to equalise the loads on two closely spaced (tandem) axles. The “quarter” of the vehicle is described as a set of rigid bodies linked with each other by spring and damping elements. The model has three degrees of freedom and defines vehicle’s responses to excitations (inputs) generated by road irregularities. The mathematical models known from the literature describe typical suspension systems and specific types of load balancing systems for two- and three-axle vehicles. This makes it impossible to apply them directly to simulation test of a vehicle with two front axles. A new model dedicated to the proposed load equalizing system, which allows simulation tests for the design and verification of the new system’s operation, has been prepared.