Research on ride comfort of complex vehicle model under non-stationary conditions

To address the technical bottleneck where high-precision modeling and efficient solution are mutually restrictive in the analysis of vehicle non-stationary random vibration, this study proposes an innovative analytical method integrating the finite element method (FEM), transient power spectral density (PSD) method, and spatial-domain pseudo-excitation method (PEM). The core principles of the transient PSD method are systematically elaborated, the relevant theoretical formulas of the spatial-domain PEM are derived, and the specific solution procedure for the vehicle FEM under non-stationary conditions is clarified. Taking a 7-degree-of-freedom (DOF) vehicle spatial model as the validation object, comparative simulation verification is conducted between the proposed method and the Monte Carlo method. The results show that the simulation curves of the two methods are in high agreement with a maximum error of only 5.32%, verifying the validity of the proposed method; meanwhile, the simulation time of the proposed method is reduced by 90.36% compared with the Monte Carlo method, which significantly improves the solution efficiency. On this basis, a complex FEM of the whole vehicle is established, and the time-frequency PSD and RMS value of vibration at the seat position under non-stationary conditions are successfully solved. In summary, the proposed method can simultaneously balance modeling accuracy and solution efficiency, providing an efficient and reliable technical support for the analysis of vehicle non-stationary random vibration and possessing favorable engineering application value.