A driver controlled fuel truck roll-over situation, including the effect of load motions on the transient comen‘ng behaviour of the vehicle, is analyzed. The vehicle velocity before entering the curve is 20 m/s. To account for steering actions a driver controller is applied. A new driver model is presented which is sensitive to the vehicle roll angle. The path deviation is reduced with this new driver model, but the risk of vehicle roll-over is increased.
A dynamic threshold value for the steering angle is used to determine a worst case situation with response to the fill level of the tank. It is found that the relative difference between rigidly suspended and rolling load is largest for a fill level of about 40%.
For three model configurations the same specified path, radius of turn of 83.3 m, is used as input for the simulations. The results show that load motions and driver behaviour influence the threshold values for roll-over. There are no consistent risk indication levels found for motions related to roll-over until roll-over actually occurs.
The environmental risk of the tractor semi-trailer fuel tank truck can be expressed by the probability of rupture of the tank during a collision due to the roll-over. The successive leakage can lead to environmental pollution due to release of fuel or a BLEVE (Boiling Liquid Expanding Vapour Explosion) which, especially in densely populated areas, can threaten the welfare of bystanders or the population in the close vicinity of the accident.
The case is studied where the tractor semi-trailer fuel tank truck after the roll-over slides over the pavement onto a tree. The tree, with a uunk diameter of 0.4 m, is assumed sufficiently strong to withstand the collision without any significant deformations. Even in that case it is found that rupture of the tank is unlikely for the accident analyzed.