A method for evaluating the FOD resistance of aeroengine blades

Abstract

The invention relates to a method for evaluating the anti-FOD ability of an aeroengine blade. In the method, the impact dynamics simulation of foreign object damage is performed on the simulated blade numerical model, and the relationship between the macroscopic characteristics of the gap and the type of foreign object, impact velocity, and impact angle is obtained. Based on this data, the foreign object damage test conditions are determined, and the air cannon is used to conduct the external simulant damage test on the simulated blade to observe the macroscopic and microscopic characteristics of the impact gap; the static stress and dynamic The stress is used as the initial static load and dynamic load of the high cycle fatigue test, and the high cycle fatigue test is carried out on the simulated blade after damage, and the high cycle fatigue strength of the blade is obtained by the step method, and the FOD resistance ability of the blade is evaluated according to the high cycle fatigue test results; The simulated foreign object damage and high cycle fatigue tests were carried out on a small number of real blades to obtain their high cycle fatigue strength, so as to verify the consistency of the test results between the simulated blades and the real blades.

Description

technical field [0001] The invention relates to the field of performance testing of aeroengine blades. Background technique [0002] During take-off and landing on the runway or aircraft carrier deck, the aero-engine running at high speed will often inhale hard objects such as stones, gravel, bolts, metal fragments, etc. When these foreign objects enter the engine, the relative speed of the compressor blades can reach 100m / s-350m / s, it will cause serious impact damage to the blades of the first few stages of compressors, especially the leading edge of the blades. In the prior art, the damage caused by hard objects such as metal and sand hitting the engine is called "foreign object damage" (abbreviated as FOD, Foreign Object Damage) [0003] If the damaged blades are not detected and treated in time, fatigue fracture failure may occur under high-frequency vibration, and the flying blades will break through the casing and even damage the blades of the subsequent compressor s...

AI Technical Summary

Problems solved by technology

However, the root cause of the fracture of the blade after being subjected to FOD is that there will be microscopic cracks, stress concentration, residual stress and microstructure damage in the damaged part formed by the impact, and the damaged part will easily become a source of fatigue under high-cycle working load and cause fatigue fracture

Moreover, the high-cycle fatigue failure of metals has a large dispersion, and the ability of the blade to resist foreign object damage can only be assessed by the number of cycles that can work after damage, which cannot effectively avoid the risk of blade failure caused by foreign object damage

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