Directional Response Analysis of Tractor-Trailer with Multi-Axle-Steering Carrying Liquid Load

As a bulk-liquid transport vehicle executes a turning maneuver, the liquid within the tank sloshes from side to side, prompting lateral and moment forces, which can result in a serious roll instability of the vehicle. It is well known that lateral acceleration forces play a key contributory role in the rollover of tankers. This paper investigates the yaw/roll dynamics of tractor-trailer with multi-axle-steering carrying a partial load of liquid during a transient steering operation for various levels of tank filling. First, the lateral acceleration forces and the vertical and lateral translations of the center of mass of a liquid-carrying tanker fitted with multi-wheel steering under conditions of steady-state steering response are presented. Next, the transient directional responses of yaw and roll angles are also studied in simulations of a lane change maneuver. The results demonstrate that the use of multi-axle-steering reduces the lateral forces caused by shifts of the liquid during steady turning, hence reducing roll and lateral instabilities of the vehicle. The present results are compared to those of a conventional tanker fitter with a single front wheel steerable axle.