高斯路谱激励下车辆非线性响应峭度研究

Research on Kurtosis of Vehicle Nonlinear Response Under Gaussian Road Spectrum Excitation

高斯路谱被广泛用于表征路面不平度,该激励下的车辆响应常被认为服从高斯分布。然而,当高斯路谱激励的幅值较大时,受非线性悬架影响,车辆响应常常呈现超高斯特性。本文首先构建高斯路谱和四分之一车辆非线性模型,在此基础上提出基于数字滤波器的车辆非线性响应计算方法,最后通过研究不同幅值的路谱激励下的车辆响应,揭示车辆非线性参数对响应峭度的影响。研究结果表明,路谱激励的幅值越大,车辆的非线性响应占总响应的比例越大,即车辆的非线性特性更容易被激发;此外,车辆响应加速度的峭度也随着路谱激励幅值的增大而增大,即车辆响应呈现明显的非高斯特性。本文的研究结果为车辆非线性悬架参数的优化设计提供理论参考。

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.