Research on Early Warning Methods for Acoustic Emission Damage in Typical Aviation Metal Materials Based on Microcrack Friction

Acoustic emission monitoring technology is extensively utilized in structural condition monitoring across various fields, including aviation and aerospace, due to its minimal material limitations, high detection sensitivity, and capability for real-time monitoring. In the context of fatigue testing for aircraft structures, the timely and accurate detection of fatigue crack initiation is crucial for effective damage monitoring. To address this challenge, we discovered that reducing the stress ratio during high-cycle fatigue tests generates a greater number of crack closure acoustic emission signals at the microcrack generation stage, thereby facilitating early damage warning. The high- and low-frequency loading strategies enhances the application of acoustic emission technology in high-noise fatigue testing environments. The effectiveness of this approach has been validated through multiple fatigue tests conducted on aluminum alloy components.