A NUMERICAL ANALYSIS OF THE BEHAVIOUR OF A VEHICLE MODEL INCLUDING DRIVER'S SEAT AT A ROAD BUMP

This paper presents a study of the results obtained by a numerical simulation of a vehicle model while driving over a road bump. In contrast to the classic, so-called full-vehicle model consisting of 7 degrees of freedom (DOF), ail additional degree of freedom, connected with the driver's seat, is taken into account. By means of a numerical Solution of the 8-degree-of-freedom model the natural frequencies as well as the vibration responses of the vehicle wheels, chassis (pitch, roll, and heave), and driver's seat are calculated ill the time and frequency domain. The excitation effects of the road bump are taken into account in two different ways, i.e. in the form of short-duration excitation, resulting in the excitation of natural frequencies of the masses in the vibration system, and in the form of periodic excitation, resulting from passing over the road bump with the front wheels and after a time delay with the rear wheels. In addition, the influence of vibration parameters, such as riding speed. driver's mass including the seat, and stiffness and damping of the driver's seat, on the vibrations of the driver's seat are analyzed.