Study On Reliability Analysis Of The Rotor System Of The Aero-engine

Aero-engine is a power device with the most stringent requirements and conditions.If we compare the aero-engine to the "heart",the rotor system of the aero-engine is the "organ" to maintain the normal operation of the "heart",that is the core component of the aero-engine.Because the working state of the rotor system is very severe and harsh,it is easy to have various forms of failure,which poses a serious threat to the normal flight of the aircraft.Therefore,it is of great significance to carry out reliability analysis to improve the safety of the rotor system of the aero-engine.This paper studies the failure analysis and multi-state reliability analysis of the rotor system,the main contents are as follows:(1)The failure mode and influence analysis(FMEA)method is applied to the rotor system based on the deep analysis of the function and structure of the rotor system.Combined with published data from home and abroad and historical test data,through the five steps of dividing the indenture level of the rotor system,analyzing the failure modes,failure causes and fault effects and determining severity.Finally,the FMEA report of the rotor system is obtained,which lays the foundation for the fault tree analysis(FTA).(2)The fault tree analysis(FTA)method is used to construct a fault tree of the rotor system failure,and the fault research which combines the qualitative analysis with the quantitative analysis is carried out.The minimum cutting machine,the minimum path set and the structural importance of the fault tree,and the corresponding improvement measures are put forward through the qualitative analysis of fault tree.There are some problems such as difficult collection of failure data,difficult connection between bottom events,and failure degree can not be quantitatively described when the fault tree of the rotor system is quantified.In order to solve these problems,the T-S model is introduced on the basis of traditional FTA.The T-S fuzzy fault tree and T-S fuzzy doors of the rotor system are constructed and the quantitative analysis the rotor system is carried out.Then,the fuzzy possibility of the rotor system failure and the T-S importance of the components are calculated.The results show that the method can make up for the shortage of the fault tree quantitative analysis,and can provide the basis for troubleshooting.(3)Based on the traditional two-state reliability analysis,the multi-state extension of reliability analysis is carried out.According to the theory of multi-state systems,the multi-state reliability analysis model of the rotor system is established.The Semi-Markov model is used to describe the performance degradation process of the components of the rotor system.The universal generating function(UGF)technique is used for the individual component multi-state modeling and utilized to exhibit the relationship between the state performance and the state probability of components.Furthermore,the UGF of the rotor system is obtained by simplifying the system structure with the modularized method.An turboprop engine rotor system is taken as an example to evaluate the reliability of the rotor system under different task performance levels.Compared with the traditional method,the analysis results indicate that the multi-state reliability analysis method can reflect the degradation process of the rotor system performance more realistically.