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Crack-Length Estimation for Structural Health Monitoring Using the High-Frequency Resonances Excited by the Energy
Roshan Joseph1, Hanfei Mei2, Asaad Migot3
1Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USA.
Sensors (Basel, Switzerland)
|July 2, 2021
Summary
A novel method uses acoustic wave signals to estimate fatigue crack length in structures. Analyzing the frequency spectrum
Area of Science:
- Materials Science
- Mechanical Engineering
- Acoustics
Background:
- Acoustic waves are crucial for structural health monitoring (SHM) in detecting fatigue cracks.
- Piezoelectric wafer active sensors (PWAS) detect acoustic waves from crack growth.
- Conventional methods struggle to precisely estimate crack length.
Purpose of the Study:
- To propose and validate a novel method for estimating fatigue crack length using acoustic wave signals.
- To analyze the relationship between crack length and acoustic signal characteristics.
Main Methods:
- Finite Element Method (FEM) analysis of acoustic wave propagation and scattering from fatigue cracks.
- Utilizing PWAS sensors to record acoustic signals generated by crack growth.
- Analyzing the frequency spectrum of acoustic signals to identify patterns related to crack length.
Main Results:
- FEM analysis predicted wave scattering patterns and acoustic signals for different crack lengths (4 mm and 8 mm).
- The frequency spectrum of acoustic signals exhibited unique peaks and valleys that varied with crack length.
- The number of spectral peaks and valleys increased with crack length.
- Experimental results closely matched FEM predictions.
Conclusions:
- The peak-valley pattern in the acoustic signal frequency spectrum can accurately determine crack length.
- This method offers a precise way to estimate crack length using acoustic signals alone.
- The findings support the use of acoustic wave analysis for advanced SHM.
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