A contribution to investigation of the damping forces in classical shock absorbers

Shock absorbers are fundamental part of the vehicle suspension. Suspensions are needed to guarantee vehicle handling, passenger riding comfort and braking. Bearing that in mind, the tire-road contact forces need to be as stable as possible. Each wheel should always remain in contact with the ground. Comfort means that vibrations, induced by road profile during riding, are of a minimal nuisance to the passengers. When designing a new vehicle, a lot of development effort is focused on the optimal choice of the suspension parameters, stiffness (including stabilisers) and damping. In this paper will be presented the results of influence of the cinematic parameters (relative: displacement, velocity and acceleration) to the force that occurs in the shock absorber. The experimental results are obtained by testing of three types of classic shock absorbers from the production of Magnety-Marelli - Turin, under the influence of random excitation. To determine the level of influence of individual cinematic parameters, the theory of the partial coherence functions was used.