Effects of Suspension Design Parameters of a Semi-trailer Truck on Vehicle Ride Comfort and Road Surface Friendliness

The objective of this study is to analyze the effects of suspension design parameters of a semi-trailer truck on vehicle ride comfort as well as road surface friendliness. A half-dynamic vehicle model with 12° of freedom is established under random road excitation. The weighted root mean square (RMS) of acceleration responses of the vertical driver’s seat, cab’s pitch and dynamic load coefficient (DLC) is chosen as an objective function which uses Matlab/Simulink software to simulate the vehicle dynamics model and calculate the objective functions. The effects of suspension design parameters of a semi-trailer truck such as stiffness and damping coefficients on the objective functions are analyzed respectively. The results show that the effects of the stiffness and damping parameters in the suspension systems on the vehicle ride comfort as well as road surface friendliness are very obvious. The worse the vehicle ride comfort as well as road surface friendliness is, the greater the stiffness of the suspension systems is. However, the vehicle ride comfort improves with the increase of the damping of the suspension systems. Therefore, the study provides a theoretical basis for the suspension system design of semi-trailer trucks.