The dynamic behavior of a vehicle body and its vertical acceleration when the vehicle passes over a speed hump are investigated. Unlike previous works, the present one takes into account an extra effort in the form of a load transfer to the vehicle body due to the rise of one of the wheels over the hump resulting in a circular motion. First, we compare the vertical acceleration of the vehicle in this model with that obtained from other models that ignore such an effort; we carry out comparisons based on experimental measurements, as well. Then we compare the vibrational behavior of the body for four vehicle types to highlight the influence of their mass on their respective behavior. Finally, the influence of the geometry of the hump on the vehicle behavior is investigated. The results demonstrate how important it is to take into consideration such additional effort on the bodywork. For speeds beyond a threshold value, wheels lift occurs and the consideration of the aforesaid effort yields very satisfactory results. However, for low speeds below the threshold value, the wheels fail to lift off the hump and it turns out that it is the fact of disregarding the aforementioned extra effort that leads to better results. It is also noted that the oscillations of the different vehicles increase with the increasing speed and with a phase shift from a vehicle to another due to differences between their front half-wheelbases. Furthermore, the amplitude of the first oscillations increases with the mass of the vehicle and the amplitudes of the oscillations increase with both the height and width of the bump, as well.

speed bump, relief of the road, obstacle, driving comfort, vertical acceleration, radius of curvature, oscillations.