Vibration Modeling and Analysis of Pipeline- Clamped Systems for Aircraft Landing Gear

Fluid pulsation within the aircraft landing gear hydraulic pipeline system can lead to severe damage to system structures such as valves, joints, and supports. Previous research has predominantly focused on investigating the vibration characteristics of the pipelines themselves, often neglecting the frequency-dependent characteristics of clamps. For the dynamic modeling of clamped pipeline systems, accurately obtaining the dynamic response of the clamps is of significant importance.This study establishes the vibration differential equations for the hydraulic pipe-clamp rigid-flexible coupling nonlinear system. The frequency-dependent dynamic properties of flexible clamps are considered based on fractional derivative theory, and the parameters of the clamp's dynamic model are identified using a genetic algorithm. Taking into account the flexible constraint of the clamps, a fluid-structure interaction frequency-domain solution method for the hydraulic pipeline-clamp system is investigated. A comparative analysis is conducted on the vibration responses, including vibration velocity, stress waves, and natural frequencies, of the hydraulic pipeline system under clamp constraints between a linear stiffness simplified model and a nonlinear stiffness fractional derivative model. The results demonstrate that the modeling method proposed in this paper can more accurately capture the dynamic characteristics of hydraulic pipelines with flexible clamps.