Design and experimental research of single-cylinder double-piston damping adjustable shock absorber

A novel large-capacity, single-cylinder, double-piston damping adjustable shock absorber was designed to address the limitations of conventional shock absorbers, which have fixed damping characteristics that are inadequate for varying road conditions. This paper primarily contributes to the conceptual design and experimental dynamic characterization of the proposed shock absorber, which includes a built-in regulating valve for an external nitrogen tank. The feasibility of the proposed damper to achieve adjustable damping characteristics across a wide range of loading conditions was investigated. To facilitate this investigation, a test rig was developed for experimental characterization across various mechanical loading scenarios. Both qualitative analyses, such as force-displacement and force-velocity characteristics, and quantitative analyses, including dynamic range, were conducted as functions of loading velocity, displacement amplitude, and gear position. The results demonstrated a maximum dynamic range of damping force during the compression stroke of 2.16 kN and a maximum output damping force of 7.05 kN. Additionally, the maximum dynamic range of damping force during the rebound stroke was found to be 2.57 kN, while the maximum output damping force was 5.97 kN. These findings confirm the potential of the proposed single-cylinder double-piston damping adjustable shock absorber for off-road suspension systems and suggest that straightforward design modifications can enhance the scalability of damping force for various applications.