Turbine disc crack propagation reliability analysis method based on quasi Monte Carlo sampling

Abstract

The invention relates to a turbine disc crack propagation reliability analysis method based on quasi Monte Carlo sampling, which comprises the following steps of: describing the time-varying dispersibility of crack propagation by using a dual-time scale function Wiener process, and establishing a turbine disc crack propagation time-varying model; carrying out parameterized modeling on the turbine disc, carrying out sensitivity analysis to determine key geometric dimensions, considering small subsample characteristics in reliability evaluation of the turbine disc based on a probability-interval characterization method, and obtaining characterization of geometric dispersity of the turbine disc; meanwhile, in order to reduce the calculation cost and improve the calculation efficiency, adopting a quasi-Monte Carlo sampling method to generate a low-difference sequence to replace a pseudo-random number to generate a sampling point for subsequent calculation; and then, carrying out fatigue crack propagation simulation on the sampling points by adopting a finite element-based turbine disc static strength analysis and a stress strength factor-based empirical formula calculation method to obtain the probability life and reliability of the turbine disc.

Description

technical field [0001] The invention relates to a reliability analysis method for the crack growth life of an aero-engine turbine disc, which is a probability life analysis method capable of considering the time-varying characteristics of crack growth dispersion and geometric dispersion, and belongs to the technical field of aerospace engines. Background technique [0002] Aeroengine turbine discs have the characteristics of high temperature, high pressure and high load due to their service conditions, and are required to meet long life and high reliability (the probability of damage to engine structural parts requires at least 10 -7 -10 -9 times / flight hours) and other harsh conditions, therefore, extremely high requirements are placed on the use and maintenance of the aero-engine turbine disc. Fatigue fracture is the main failure mode of aero-engine turbine disk. Due to the influence of material preparation, processing technology and other factors, the microstructure of t...

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Problems solved by technology

The present invention not only considers the time-varying characteristics of crack growth dispersion and the influence of the randomness of turbine disk geometric size on fatigue crack growth life, b

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