Abstract
Abstract: The number of unknowns is more numerous than the number of equations in the motion equations of a motor vehicle. For that reason to determine the distribution of the contact forces with the road there are necessary additional suppositions. One of these suppositions takes into account the neglect of the car body´s strains. Under the circumstances it is considered that the vertical forces are proportional to the displacements on vertically of the suspension fixing points. Consequently there are determined the vertical forces at the four wheels. There are presented the dependences of these ones depending on: the acceleration on the longitudinal direction, the speed and the angular acceleration of the motor vehicle, the mass and the additional weight and the distribution of this one by the coordinates compared to the theoretical center of the road vehicle. These are particularized the relations obtained for the passing over from the rectilinear motion to the circular motion, presenting the variations of the vertical forces depending on the angle between the speed of the mass center and the longitudinal axis of the vehicle. There are also determined the limit values of these forces taking into account that the motion of the mass center is circular. Therefore it is observed a burden of the vehicle´s exterior part, overloaded being the front wheel exterior to the bend. At the same time it is observed a discharged especially at the back wheel interior to the bend. It is also determined the critical velocity at which the vertical reactions at the back interior wheel becomes null, so appearing the danger of the side slipping.
Keywords: vertical forces, non steady motion