Abstract
This paper is concerned with the running stability of tractor-semitrailer combination at braking. Firstly, we construct nonlinear equations of motion for the articulated vehicles, which have 9 degrees of freedom. Secondly, simulation study is carried out to show the vehicle performance in realistic situation. Jack-knifing on the straight road section was recreated by the simulation in consideration of road gradient not only longitudinal direction but also lateral direction. By using the concept of load rate of each tire, we confirmed that the model shows the mechanism of the jack-knifing on straight road section, and the motion of limit performance conditions. Finally, the relationship between limit performance, road gradient condition, and vehicle parameters is shown. These results emphasize the importance of observation of the tire load rate. Especially, rear axle of tractor should be considered when we discuss the limit performance of jack-knifing.
