Study on Effects of Road Conditions on the Lateral Instability of Tractor Semitrailer Vehicle during Turning Maneuver

Instability of vehicle can be defined as an unexpected response maneuver that induces disturbance, occurring in the ground plane. This can include the longitudinal, lateral, pitch, yaw, roll direction, or their combinations. Many tractor semitrailer vehicle accidents can be caused by lateral instabilities which may be classified into two types: rollover and yaw instability. Rollover occurs when centrifugal forces imposed on the vehicle during a maneuver exceed the rollover threshold of the vehicle. Yaw instability often occurs in tractor semitrailer vehicles during turning maneuver on the road with low friction coefficient. The yaw instability is shown by the loss of motion trajectory or Jack-knife. This paper establishes a dynamic model of tractor semitrailer vehicle, based on Multi-Body System Method analysis and Newton-Euler equations with Burckhardt’s tire model. This model is applied to evaluate the effect of road conditions on lateral instability of the tractor semitrailer vehicle during turning maneuver. The results can serve as the basis for determining the early warning and controlling the lateral instability of tractor semitrailer vehicle with the dynamic model.