| Gaussian road spectrum is widely used to characterize road roughness, and the vehicle response under this excitation is often considered to obey Gaussian distribution. However, when the amplitude of Gaussian road spectrum excitation is large, the vehicle response often presents super-Gaussian characteristics due to the influence of nonlinear suspension. In this paper, firstly, Gaussian road spectrum and a quarter vehicle nonlinear model are constructed, and then a calculation method of vehicle nonlinear response based on digital filter is proposed. Finally, the influence of vehicle nonlinear parameters on response kurtosis is revealed by studying vehicle responses excited by road spectrum with different amplitudes. The results show that the greater the amplitude of road spectrum excitation, the greater the proportion of nonlinear response of vehicles to the total response, that is, the nonlinear characteristics of vehicles are more likely to be excited. In addition, the kurtosis of vehicle response acceleration also increases with the increase of road spectrum excitation amplitude, that is, the vehicle response presents obvious non-Gaussian characteristics. The research results of this paper provide theoretical reference for the optimal design of vehicle nonlinear suspension parameters. |