ON A SUBCLASS OF NONLINEAR PASSIVE AND SEMI-ACTIVE DAMPING FOR VIBRATION ISOLATION

A quarter-car model incorporating nonlinear passive and active dampings is studied. The former includes asymmetric, quadratic law and acceleration sensitive dampers while the latter includes a semi-active damper. The vehicle is traversing a roadway which contains randomly distributed irregularities. The road excitation is modeled as a stationary Gaussian colored noise. The performance boundaries of linear passive suspension in terms of ride comfort, road-holding ability and suspension working space are first defined. The performance capabilities of the different concepts of suspension damping are then evaluated and compared. The results have shown that, among the alternative forms of damping, the semi-active damper evolves as the one which has a good potential in simultaneously isolating the car body and controlling the wheel-hop motion. Therefore, further study is carried out on a half-car model incorporating semi-active controllable dampers to reveal the performance capabilities of such a system over a representative range of operating conditions. © 1990.