Turbine disc multi-failure-mode reliability optimization method based on EGRA

Abstract

The invention relates to a turbine disc multi-failure-mode reliability optimization method based on EGRA, and the method comprises the steps: (1) carrying out the parametric modeling of a turbine discsector, analyzing the geometric parameter sensitivity of a turbine disc, and selecting a design variable; (2) performing LHC sampling on the design variables, calculating the service life of each sampling point under each failure mode, and establishing a reliability model of each failure mode; (3) evaluating the reliability model of each failure mode by using an efficient global reliability analysis (EGRA) method, and if the reliability model of each failure mode is greater than a convergence limit, adding sample points into the initial model until the model converges; (4) fitting the servicelife in each failure mode by using the reliability model updated in the step (3); and obtaining the system service life according to the related form and carrying out optimization solution on the system service life, if the optimization result does not meet the system reliability requirement, calculating the optimal point real service life value, adding the optimal point real service life value into the reliability model to update the model, and repeating the steps of checking convergence and updating the model until the system reliability is met to obtain the optimization result.

Description

technical field [0001] The invention is a reliability optimization method for aero-engine turbine disks with multiple failure modes, in particular, it is a reliability optimization method for turbine disks with multiple failure modes based on EGRA, which can consider the reliability of sampling from different parts and multiple failure modes An optimization design method belongs to the technical field of aerospace engines. Background technique [0002] Aero-engine is an extreme product, which works under complex loads / environments such as high temperature, high pressure, and high speed; the improvement of engine performance and safety indicators requires the engine to be light in weight, long life, and high reliability (for example, safe flight Engine structural parts require a low probability of failure, up to 10 -5 -10 -7 times / flight hour). The traditional reliability analysis method only considers the fatigue life of a single dangerous point under a single failure mod...

AI Technical Summary

Problems solved by technology

In fact, there are some failure modes that have little impact on the system, and expensive sequence sampling is used for these failure modes that have little impact on system failure, resulting in a large amount of waste of calculation.

The present invention combines the EGRA method with multiple failure modes of the turbine disk, considers the working environment where low-cycle fatigue and creep-fatigue act simultaneously, and establishes the EFF function of multiple failure modes according to the correlation form between different failure modes, and directly compares the multiple failure modes The EFF function analysis of the failure mode concentrates the sequence sampling sample points near the limit state boundary of the multi-failure mode system, while ensuring high analysis accuracy for the multi-failure mode system of the turbine disk, it reduces the distribution of the sequence sample points in the system In the unimportant area of ​​failure, the number of sample points is reduced, and the efficiency of reliability analysis of multi-failure mode systems is improved Method" (Patent No. CN201611266927.5, Announcement No.: CN106644784A) considered three typical failure modes of turbine discs, predicted life based on test data, and discussed the influence of each failure mode on the life of turbine discs, but did not consider many The Correlation Between Failure Modes and the Simultaneous Effects of Multiple Failure Modes on Turbine Disks

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