Vibration Reduction Characteristics and Vibration Control of Aviation Hydraulic Pipeline by Hard Coating

Aviation hydraulic pipelines are an important channel for power transmission in aviation hydraulic systems. Due to long-term exposure to complex vibration environments, hydraulic pipeline systems are susceptible to accumulated fatigue damage failure, which poses a great threat to aircraft safety and reliability. At present, there are only passive ways to reduce hydraulic pipeline vibration, such as adding vibration isolators and damping bearings. These methods have a poor vibration damping effect and are not safe. In this study, a hard coating was used as a new vibration reduction method for aviation hydraulic pipelines to reduce the damage caused by vibrations. For this purpose, three different hard-coating materials were optimally selected, and model creation, finite element analysis, and experimental research were carried out to study the vibration responses of hard-coated aviation hydraulic pipelines under the actual working conditions of an aircraft. The optimal solution was obtained through orthogonal experiments. The vibration reduction rate of the aviation hydraulic pipelines could reach 20.33% under the constant-frequency excitation of the low-pressure rotor of the engine, and the vibration reduction rate under the constant-frequency excitation of the high-pressure rotor could reach 26.60%. The rationality of the model was verified, and it was proven that the hard coating could meet the demands of vibration control in practical engineering and provide a reference for the vibration analysis and vibration control design of aviation hydraulic piping systems.