Abstract
The reliability of aero engine has a direct impact on the flight safety of the whole plane. With the continuous improvement of performance requirements of aero engines, the related fatigue and reliability problems also appear. For the fatigue failure characteristics of the typical component (compressor disk) in an aero engine, the fatigue reliability of its multi-site damage structure in service is analyzed by using probability cumulative damage criterion in this paper. The probability distribution definitions of life, damage and damage threshold are discussed and the relationship among them is also introduced by the new proposed criterion. Meanwhile, a method to determine the probability distribution of cumulative damage threshold and probability life prediction is carried out, based on which a hierarchical index system of statistical analysis and reliability modeling principle on the system level is further constructed for compressor disk. At the end of the paper, a certain cruise of fighter plane is analyzed to verify the validity of the new model. Emphasizing the difference between the compressor disk and traditional component, the new reliability analysis model developed in this study is basically reasonable for most of the load histories for the compressor disk, other than the traditional one, especially for the changeable and complex cruise missions.
Highlights
The reliability of an aero engine has direct effects on the safety of the plane
Among various components of aero engine, the related fatigue reliability issue of compressor disk has attracted the attention of scholars due to its complicated structure and the load environment [2,3]
According to the failure probability analysis of the system and the probability cumulative damage calculation of the specific damage location, a multi-site damage assessment and fatigue reliability analysis model suitable for aero engine compressor disk in the process of complex tasks is established in this paper
Summary
The reliability of an aero engine has direct effects on the safety of the plane. With the continuous improvement of performance requirements for aero engines, the engine rotors with lighter structure mass, larger workload and higher endurance temperature are required, for which the related fatigue and reliability issues are subsequently exposed [1]. Questions about the fatigue life of a simple part and the probability distribution of fatigue life under a deterministic cyclic load corresponding to a certain reliability are traditionally predicted based on stress-probability life (P-S-N) curve [20,21,22,23] or using the stress-strength interference model, for which the influence of load uncertainty on fatigue failure probability needs to be considered [24,25,26]. The problem of fatigue failure probability under variable amplitude load history is more complicated, but various studies are limited to specific parts or structures with multi-site damage rarely being taken into account [27,28,29,30]. According to the failure probability analysis of the system and the probability cumulative damage calculation of the specific damage location, a multi-site damage assessment and fatigue reliability analysis model suitable for aero engine compressor disk in the process of complex tasks is established in this paper
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