Identification and sensitivity analysis of vehicle body compound vibration

In the paper, the mechanism and key influencing factors of compound vibration are analyzed by establishing the dynamic mathematical model with 11 degrees of freedom, and the experiment method for identifying compound vibration is put forward. The sensitivity of influencing factors of compound vibration of the body is analyzed by establishing a rigid-flexible coupling dynamic simulation model. The results show that vertical vibration, roll vibration and pitch vibration are the main forms of the vehicle body vibration, front suspension stiffness and rear suspension stiffness not only are the key influencing factors of Z-direction vibration, but also are the key influencing factors of pitch angle. The key influencing factors of roll angle are lower control arm length LD and rear suspension damping Cr. By optimizing and improving the damping of the rear shock absorber, the Z-vibration, roll vibration and pitch vibration of the body are obviously reduced. The research results provide a theoretical basis and reference for mastering the composition and formation mechanism of compound vibration of vehicle body.