THE EFFECT OF ROAD OBSTACLES ON THE DY

Abstract

The thesis concerned with the effect of the passing of the sedan car tyre over an obstacle (Cat’s Eye) at various car speeds, inflation pressure tyre and load conditions on the mechanical vibrations of the sprung and unsprung masses. The measurement of the mechanical vibrations was made by installing two accelerometers on the sprung and unsprung masses on the fixation points of the suspension with the car’s body. The mechanical vibrations were measured and recorded during the car’s movement by a laptop, data acquisition card and software designed to record the experimental results in a specific files for each experiment. The value of the acceleration of the mechanical vibrations is an indicator for the dynamic forces on the tyre and they are in proportion with each other. The experimental and the theoretical work show that passing over the cat’s eyes has a great effect on the dynamic forces that effect on the tires. The change of the speed of the vehicle has a distinguish effect on the vertical acceleration that transmits from the road to the tires and the vehicle body more than the change in both tyre inflation pressure and load conditions.