Influence of damper characteristics parameters on the handling stability performance of vehicles

Abstract

The effect mechanism of damper damping characteristics on vehicle handling dynamics remains insufficiently explored. This paper reveals the influence of hydraulic damper characteristics parameters on vehicle handling stability performance, basing on vehicle dynamics simulation analysis. The damper damping characteristics can systematically be described by the damper characteristics parameters, including the damper damping coefficient, asymmetry ratio, and safety ratio (i.e. the ratio of damping coefficients before and after the opening of the recovery valve on the damper rebound stroke). The influence analysis includes the reflection relationships between damper characteristic parameters and vehicle transverse acceleration, yaw angular velocity, sideslip angle, and car body roll angle. Firstly, based on vehicle system dynamics theory, a longitudinal-lateral-vertical coupled dynamic vehicle model is established, considering the nonlinear damping effects of the damper. The model's effectiveness is then verified by CarSim simulation comparisons. Subsequently, using vehicle dynamics simulation, the variation patterns of the vehicle lateral-vertical dynamic response with damper characteristics parameters are investigated under two typical handling tests. The simulation results show that under the double lane-change condition, the lateral acceleration and yaw rate are positively correlated with the damping coefficient and the asymmetry ratio, and inversely proportional to the safety ratio. The lateral acceleration increase with the increase of the damping coefficient and asymmetry ratio, while the roll angle decreases; the response pattern of safety ratio to handling stability is the opposite. Under the step steer condition, the vehicle yaw rate increases with the increase of the damping coefficient and asymmetry ratio, while the roll angle and lateral acceleration decrease; the influence pattern of the safety ratio is the opposite. The influence of damper characteristics parameters on the sideslip angle is relatively small. This study can provide theoretical guidance for the design, optimization, and secondary development of hydraulic dampers.