An egra-based multi-failure mode reliability optimization method for turbine disks

Abstract

The invention relates to an EGRA-based multi-failure mode reliability optimization method for a turbine disk. The steps are: (1) parametrically model the turbine disk sector, analyze the sensitivity of the turbine disk geometric parameters, and select design variables; The design variables are sampled by LHC, and the life under each failure mode at each sampling point is calculated separately, and the reliability model of each failure mode is established; (3) the reliability model of each failure mode is analyzed by the efficient global reliability analysis method (EGRA) Evaluation, if it is greater than the convergence limit, add sample points to the initial model until the model converges; (4) Use the reliability model updated in (3) to fit the life under each failure mode, and obtain the system life according to the relevant form and compare it to Carry out an optimization solution, if the optimization result does not meet the system reliability requirements, calculate the real life value of the best point, and add it to the reliability model to update the model, repeat the steps of checking convergence and updating the model until the system reliability is met, and the optimization result is obtained .

Description

technical field [0001] The present invention is a reliability optimization method for multiple failure modes of an aero-engine turbine disk, in particular, it is an EGRA-based reliability optimization method for multiple failure modes of a turbine disk, which can consider the reliability of different parts sampling and multiple failure modes An optimization design method belongs to the technical field of aerospace engines. Background technique [0002] Aeroengine is an extreme product, working 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 in life, and high in reliability (for example, for safe flight Engine structural parts require a low probability of failure, up to 10 -5 -10 -7 times / flight hour). Traditional reliability analysis methods only consider the fatigue life of a single dangerous point under a single failure mo...

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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