Based On Permutation Entropy In The Diagnosis Of Air Bear And Finite Element Analysis

With the rapid development of science and technology,the performance of aeroengine continues to increase,raising more and more stringent requirements on the speed and load of aeroengine bearings.Long-term work under high speed and heavy load bearing often shows stress is too large,the temperature is too high and other characteristics,the occurrence of abrasions,burns and other failure,serious will bring serious consequences such as bearing stuck axis.Bearing failure directly affects the performance of the entire engine,resulting in huge economic losses and social hazards.Therefore,it is very necessary to diagnose the early failure of aviation bearings.First of all,through the bearing fault experiment,the vibration signal of the bearing is collected.The vibration signal of the bearing is analyzed by Coinv DASP V11 signal analysis system.The vibration amplitude of the bearing is compared with that of the normal bearing,and the vibration amplitude of the fault bearing is found within the bearing The natural frequency of the ring,the outer ring and the rolling element showed a large peak.As the degree of bearing failure gradually increased,the amplitude of the vibration of the bearing also increased continuously.The vibration amplitude of the three kinds of mild,moderate and severe failures The difference between the values is obvious,and the vibration amplitude of the fault signal is obviously larger than that of the normal signal.Secondly,the permutation entropy algorithm is introduced into the fault diagnosis of aviation bearings.The theory of permutation entropy algorithm is introduced.The permutation entropy algorithm is analyzed.The permutation entropy is used to extract the vibration characteristics of aeroengine bearings.Based on the Hertz contact theory,the contact characteristics of the bearing were studied and analyzed by ANSYS finite element analysis software.The theoretical and analytical values were compared to verify the feasibility of the finite element simulation.At the same time,different loads are applied to the bearing,and the connection between different loads and bearing failure is analyzed.Finally,the bearing calorific value calculation model is studied to determine the reasonable thermal load and thermal boundary conditions for the finite element simulation.The steady-state thermal analysis is carried out in the finite element analysis software,and the heat of the deep groove ball bearing under different loads and operating speeds is obtained Distribution,find out the impact of thermal load on bearing failure.Considering the influence of load,temperature and operating speed on contact and contact strain of bearing,the analysis results under the coupling of thermo-stress are obtained by nominal stress method,and the change of failure probability of bearing under different working conditions is considered.The finite element modal analysis method is used to analyze the variation of natural frequency,mode shape and vibration amplitude of the first five bearings.The simulation resultsare analyzed to find out the relationship between natural frequency and vibration amplitude and reduce the probability of bearing failure.