| The aircraft hydraulic pipeline system plays an important role in medium and energy transmission.The pipelines are cascaded,with complex structures and numerous numbers.They are subjected to extremely external complicated loads.As a result,the hydraulic pipeline system becomes one of aircraft components with the highest failure rate.The clamp is applied to enhance the rigidity,achieve vibration control,and then extend the service life of the pipeline system.Therefore,the characteristics of the hydraulic pipeline clamps and the dynamic behavior of the pipeline system with clamps are analyzed,which is significant to the design the aircraft hydraulic pipeline system,achieve vibration control under the full flight profile and improve aircraft reliability.The main research contents are as follows:(1)According to the straight pipeline,the elbow pipeline,and the pipeline in the ARJ21-700 front fuselage region,the dynamic mathematical models were establish respectively by the transfer matrix method.The efficient and accurate solution of the model was researched.The inherent characteristics of the above hydraulic pipelines were analyzed in the ABAQUS software platform.By using the experimental platform of the aviation hydraulic pipeline,the modal knocking test was conducted on the experimental pipeline.The accuracy of the inherent characteristics of the hydraulic pipeline based on the transfer matrix method and the ABAQUS software finite element method was verified.It will lay the foundation for the follow-up study of the pipeline system dynamics analysis.(2)For the P-type clamps in aviation hydraulic pipeline system,the finite element analysis model was established in the ABAQUS software platform.Since P-type clamp gaskets are super-elastic rubber materials,it is necessary to consider the viscoelastic effects and to set constitutive model parameters.The finite element analysis of the translational equivalent stiffness and rotational equivalent stiffness of the six degrees of freedom is carried out.The equivalent stiffness verification experiment is designed to verify the simulation results,which will provide the equivalent stiffness data for the hydraulic piping system with supporting.(3)In the ARJ21-700 left wing region,the partial hydraulic pipeline system with P-clamp is taken as the research object.The finite element analysis model of the hydraulic pipeline system was established based on the equivalent stiffness of the six degrees of freedom for the P-type clamp.The load condition(displacement,temperature,vibration load)that causes the high failure rate of the aircraft hydraulic pipeline system is chosen as the analysis load.The finite element analysis of the pipeline system is performed to obtain the root mean square stress and the Mises stress,and then its strength and fatigue life are evaluated.The stress and strain of pipeline system under superposition of temperature and pressure load is verified by experiments,which will provide the reference for the layout,analysis and design of the aircraft hydraulic system with supporting. |
