Nonlinear modeling and analysis of position-dependent damper with hydraulic rebound stop system for commercial vehicles considering fluid-structure interaction

To address the failure of traditional bumpers in commercial vehicle dampers under large-stroke conditions, a position-dependent damper with hydraulic rebound stop system is proposed. A whole three-dimensional fluid-structure interaction dynamic model incorporating contact nonlinearity is established to accurately capture the transient response and damping characteristics of the proposed damper. Specifically, the direct coupling method is employed during the opening state of the valve system, while the indirect coupling method is adopted in the non-opening and maximum opening states. Additionally, fluid models of the hydraulic rebound stop system are constructed based on displacement sensitivity characteristics. After experimentally validating the model’s reliability, a comprehensive analysis is conducted on the internal flow field characteristics, the dynamic behavior of the stacked valve discs, and the damping characteristic of the hydraulic rebound stop system, with comparisons made against the damping characteristics observed under conventional conditions. The results show that the designed damper significantly enhances the damping force at the rebound stroke limit, and the additional damping force shows a significant inverse correlation with the gap between the guide seat and the limited block. These findings provide valuable guidance for the design of position-dependent dampers.