Finite Element Analysis Of Pipeline And Connection In Aircraft’s Hydraulic System

Aircraft’s hydraulic system is airplane’s main executive system which enables it to accomplish all the actions, and it is a key system to ensure flight safety. The sealing performance of pipeline connections and the vibration characteristic of pipes in hydraulic systems are the main factors that affect hydraulic system working in safety. Liquid leak caused by sealing damage in pipeline connections and structural damages caused by pipes vibration are two common failure modes in hydraulic system;Both could lead to disasters that threaten people and goods security. Therefore, it is important to study the contact problem involved in the sealing process of connections and the fluid-structure interaction(FSI) problem involved in the pipes vibration.In this paper, the research work about the pipe and connection in aircraft’s hydraulic system involves the following aspects:1) Study the rationale for contact problem involved in the sealing process of connections andthe basic method for the finite element analysis of contact problem.2) Taking the two ferrule bite type fitting as an example, a reasonable range of preloadmagnitude is carried out by the finite element analysis of the sealing process using MSC.NASTRAN software.3) Study the mechanism of FSI problem involved in the pipes vibration and derive the motionequation and the finite element equation about it.4) Conduct the modal analysis of pipes, as well as the transient analysis under basementexcitation. Then find out the influence of the structure support and pipe length on the vibration characteristic of pipes.