Abstract
Keywords:
Commercial vehicle rollover, Sensitivity analysis
Abstract
Vehicle rollover accidents are a major cause for concern, particularly for commercial vehicles which are prone to this type of accident because of their relatively large C.G height/track width ratios. In this paper, the characteristics of rollover under dynamic conditions were analysed using a three DOF vehicle model. Using a sinusoidal steering input, which represents a lane changing manoeuvre, various vehicle parameter sensitivities including longitudinal load shift effect were investigated and those sensitivities were compared each other. From this research, the effects of vehicle parameter, weight and dimension on dynamic rollover were found from the dynamic model simulation. The change of vehicle C.G height is the most influential factor affecting roll stability of all simulated parameters. Cornering stiffness change is the second largest affecting factor on vehicle rollover. Then, the change of the vehicle weight, suspension roll stiffness and damper stiffness comes next in the order of magnitude of effect. Other point is the C.G position in the longitudinal direction. For commercial vehicles, there can be big difference between the unloaded and the loaded vehicle C.G positions not only in the vertical but also in the longitudinal direction. Shifting the C.G position to the rear can cause the vehicle to unstable in both aspects of handling and rolling. Consequently, both loaded and unloaded conditions should be considered carefully in terms of roll stability to be a good vehicle design.