A Crack Prediction Method for Aeroengine Blades

Abstract

The invention provides an aeroengine blade crack predicting method and belongs to the technical field of aeroengines. According to the aeroengine blade crack predicting method, through adoption of built-in APDL of ANSYS, real fatigue crack blade models according to different crack types and crack sizes can be established quickly and accurately, displacement vibration response data in an acceleration process of the tail edges of blade apexes on blades, contact pressure on crack surfaces and dynamic stress at blade roots are extracted conveniently, and cracks in the blades can be subjected to qualitative diagnosis. Compared with traditional tests, the aeroengine blade crack predicting method has the advantages that test costs can be reduced greatly, and abundant fault information such as inherent characteristics, dynamic stress and contact pressure distribution on the crack surfaces can be obtained as a reference to diagnose cracked blades.

Description

technical field [0001] The invention belongs to the technical field of aero-engines, and in particular relates to a crack prediction method for an aero-engine blade. Background technique [0002] As one of the core components of rotating machinery (such as gas turbines, aeroengines, wind generators, etc.), blades often determine the performance of the whole machine; taking high-pressure turbine blades of aeroengines as an example, they often work In the environment, it is often subjected to the alternating action of multiple loads such as centrifugal force, aerodynamic force, and thermal stress, which can easily induce fatigue cracks; therefore, it is necessary to study the fault characteristics of cracked blades to realize early warning of cracked blades and replace them in time Fatigue damages blades, prolongs engine life, saves costs, and ensures personnel safety; [0003] Currently, vibration-based measurements are the most widely used method for crack diagnosis. In ad...

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Problems solved by technology

Compared with the plate model and the real blade model, the beam model has a simple structure and a more mature theory, so it has been adopted by many scholars, and some vibration fault signals induced by cracks are qualitatively studied based on the beam model; the plate / shell model is difficult to consider the complex nature of the real blade. Torsion and variable cross-section characteristics, and related research is mostly carried out from strength and fatigue life; cracked beam model and cracked plate / shell model cannot describe some real fatigue cracks; in addition, based on experimental methods to study vibration failure caused by cracked blades Signals are also used by many researchers, but the cost of the experiment is high, and the amount of useful information obtained is less

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