Abstract
Keywords: modelling, vehicle combination, stability
Transportation of goods by road is growing fast. Therefore there is a tendency towards longer and heavier vehicle combinations in Europe. Vehicle combination weight dimensions and configuration determine mainly the characteristics of lateral stability of articulated heavy vehicle combinations. The aim of this study is to examine the lateral dynamics and stability of three different 60 ton vehicle combinations used on Finnish roads. The stability of vehicle combinations is examined with open- and closed-loop manoeuvres using simulation models. In Finland the maximum gross weight of an articulated heavy vehicle combination is 60 tons in national traffic. The type of a heavy 60 ton vehicle combination may be a traditional Finnish truck and drawbar trailer combination or a modular combination. The maximum length of a traditional truck and a drawbar trailer combination is 22 meters and for modular combinations 25.25 meters. To achieve the maximum gross weight of 60 tons the combination must be equipped with at least seven axles. Modular combinations examined in this study consist of a towing unit coupled to a dolly and a semitrailer and a tractor coupled to a semitrailer and a centre axle trailer. EU directive has allowed the use of modular combinations in Finland since 1997. This study focuses on the effect of vehicle combination configuration and loading parameters on the handling and the dynamic stability. The dynamics of vehicle combinations is studied with openand closed loop manoeuvres using multi-body models. Experimental measures made with a heavy vehicle combination are used to verify a model. This study gives information for authorities and drivers about the influence of design parameters and loading on vehicle stability from the point of view of traffic safety. This study continues the work made for Ministry of Transport and Communications of Finland.