Research On The Dynamics And Rub Impact Fault Characteristics Of Rotating Flexible Disk

The aero-engine is known as "Pearl of the crown of modern industry",and they are the base of national defense air force and air transportation.The aero-engine consists of intake device,compressor,combustion chamber,gas turbine and tail nozzle.The compressor disk is one of the key rotating components of the aero-engine.It has the transmission power and the function of the fixed supporting blades.The working conditions of the flexible disk are harsh,and besides being very high centrifugal load,they are also affected by aerodynamic forces.With the increase of engine thrust weight ratio of components is more and more light,more and more thin,increase disk vibration,so we have to consider the dynamic characteristics of flexible disk.Therefore,it is necessary to establish a reasonable mathematical model to analyze the dynamic characteristics of flexible disk and understand its complex changing rules.In this paper,aero-engine flexible disk is taken as the research object.Based on the theory of elasticity and rotor dynamics,the energy method is used to establish the dynamic differential equation of flexible disk.According to the principle of mechanical vibration,the dynamic characteristics are studied,and the vibration response under the impact of rubbing force is analyzed.Finally,the theoretical analysis is verified through experiments.This article mainly in the following aspects:First of all,based on the theory of thin plate vibration,established the mathematical model of flexible wheel,considering the centrifugal force and the Coriolis force on the flexible disk,the discretization method and Lagrange equation,the dynamic differential equations of flexible disk and the eccentric disk flexibility is derived,and compared with the literature.Then,the inherent characteristics of the model are discussed,and the influence of geometric factors on the inherent characteristics and the vibration response of the harmonic excitation are analyzed.The results show that it is necessary to carry out modeling analysis of flexible disk.Secondly,by using numerical method,the dynamic model of the rubbing of the eccentric flexible disk was established.The vibration response characteristics of the flexible disk under the impact of rubbing force were discussed,and studied the rubbing stiffness,rubbing clearance and friction coefficient and the influence of rotating speed of rubbing vibration response.The results show that the flexible disk is very sensitive.Finally,in order to verify the theoretical analysis results,the natural frequency of the static flexible disk is experimentally studied,and the experimental results and theoretical analysis have achieved good results.