Dynamics of a quarter car system with amplitude selective damping

An amplitude-selective damping is a phenomenon in hydraulic shock absorbers where a pressure drop is a function of physical displacement even at a constant flow rate. The combination is often claimed to provide less damping for small displacement inputs as well as ordinary ride on vehicles. At the same time the system offers good ride and handling metrics by augmenting the damping force during such vehicle manoeuvres. Therefore, the purpose of this study is to investigate the dynamic performance of a simple two-degree-of-freedom (2DOF) system with an amplitude-selective damping type shock absorber. In the paper the authors derive & analyze a model of the shock absorber on a component level, then study the influence the device has on the suspension behaviour within the prescribed range of frequencies.