FREQUENCY-RESPONSE ANALYSIS OF SYMMETRICAL AND ASYMMETRIC NONLINEAR VEHICLE SUSPENSIONS

Frequency Response characteristics of a symmetric and asymmetric vehic le suspension are analyzed in the convenient frequency domain using a local equivalent linearization methodology. Suspension non-linearities include a progressively hardening stiffness and asymmetric damping ch aracteristic due to a multi-phase shock absorber. The methodology, bas ed on the principle of energy similarity, characterizes the nonlinear suspension elements by an array of local constants as function of loca l excitation frequency and amplitude, response and type of nonlinearit y. The nonlinear behaviour of the system can thus be predicted quite a ccurately in the entire frequency range. The frequency response charac teristics of a vehicle model with nonlinear suspension are evaluated u sing local linearization algorithm and compared to those established f rom direct integration to demonstrate the effectiveness of the algorit hm for different amplitudes of excitation, in the entire frequency ran ge.