FREQUENCY-RESPONSE ANALYSIS OF SYMMETRICAL AND ASYMMETRIC NONLINEAR VEHICLE SUSPENSIONS

Frequency Response characteristics of a symmetric and asymmetric vehicle 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 characteristic due to a multi-phase shock absorber. The methodology, based on the principle of energy similarity, characterizes the nonlinear suspension elements by an array of local constants as function of local excitation frequency and amplitude, response and type of nonlinearity. The nonlinear behaviour of the system can thus be predicted quite accurately in the entire frequency range. The frequency response characteristics of a vehicle model with nonlinear suspension are evaluated using local linearization algorithm and compared to those established from direct integration to demonstrate the effectiveness of the algorithm for different amplitudes of excitation, in the entire frequency range.