Simulation study on ride comfort of three-axle heavy vehicle spatial model based on rigid-elastic model and pseudo-excitation method

This research aims to develop a new ride comfort simulation technology for a three-axle heavy vehicle. To consider the elasticity of the frame, the finite element method (FEM) is used to analyze the free mode of the frame, and the elastic information of the frame is obtained. Based on the theory of rigid-elastic synthesis, a 17-degree-of-freedom (DOF) spatial rigid-elastic model of a three-axle heavy vehicle is established. The pseudo-excitation method (PEM) is adopted to improve the efficiency of the solution, thereby solving this problem. The pseudo road excitation is constructed, the pseudo responses of the vibration system and the response variables are derived, and the power spectral densities (PSDs) and the root mean square (RMS) values of the responses are deduced. Twenty response variables are used, including accelerations, suspension dynamic deflections, and relative dynamic loads of wheels, whose PSDs and RMS variables are used as evaluation indexes. Finally, a comparative study of ride comfort simulation is conducted. A comparison of the simulation results of the rigid-elastic and rigid models indicates that the elasticity of the frame considerably influences the ride comfort of the heavy vehicle and hence cannot be ignored in the study of this issue. Meanwhile, a comparison of the results of PEM and the Fourier method for the spatial rigid-elastic model of the three-axle heavy vehicle shows that PEM is accurate yet simpler and more efficient than the Fourier method. Therefore, the innovative simulation technology proposed in this work is practical and efficient and can reflect the essence of the problem.