Prediction of Fatigue Crack Growth in Gas Turbine Engine Blades Using Acoustic Emission.

Zhiheng Zhang,Kun Hu,Guoan Yang

doi:10.3390/s18051321

Zhiheng Zhang, Kun Hu + Show 1 more

Open Access

https://doi.org/10.3390/s18051321

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Abstract

Fatigue failure is the main type of failure that occurs in gas turbine engine blades and an online monitoring method for detecting fatigue cracks in blades is urgently needed. Therefore, in this present study, we propose the use of acoustic emission (AE) monitoring for the online identification of the blade status. Experiments on fatigue crack propagation based on the AE monitoring of gas turbine engine blades and TC11 titanium alloy plates were conducted. The relationship between the cumulative AE hits and the fatigue crack length was established, before a method of using the AE parameters to determine the crack propagation stage was proposed. A method for predicting the degree of crack propagation and residual fatigue life based on the AE energy was obtained. The results provide a new method for the online monitoring of cracks in the gas turbine engine blade.

Highlights

Gas turbine engines, which are known as the “heart” of aircrafts, are a type of large-scale equipment that require high reliability and extremely sophisticated technology
We propose the use of acoustic emission (AE) monitoring technology for the online identification of the blade state
AE-based fatigue monitoring tests were performed on the gas turbine engine blade and TC11 titanium alloy plate specimens

Summary

Introduction

Gas turbine engines, which are known as the “heart” of aircrafts, are a type of large-scale equipment that require high reliability and extremely sophisticated technology. The blades operate in a very harsh environment During each flight, they are subjected to the combined effects of high- and low-cycle loads, including centrifugal tensile stress and centrifugal bending moments, aerodynamic stress and aerodynamic bending moments, thermal stress and vibration as well as alternating stress [2]. Because the compressor blades are located in the front of the gas turbine engine, they are vulnerable to atmospheric corrosion and the impact of dust, sand, birds and other foreign objects in the high-speed intake airflow [3]. Research on the structural failure of engines has shown that high-cycle fatigue failure is the primary failure mode. About 25% of gas turbine engine accidents are caused by high-cycle fatigue [5]

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Discussion

Conclusion