A comparative study of fatigue damage sensing in aluminum alloys using electrical impedance and laser ultrasonic methods

Lindsey Channels, Debejyo Chakraborty, Brad Butrym, Narayan Kovvali, James Spicer, Antonia Papandreou-Suppappola, Mana Afshari, Daniel Inman, Aditi Chattopadhyay

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

Fatigue damage sensing and measurement in aluminum alloys is critical to estimating the residual useful lifetime of a range of aircraft structural components. In this work, we present electrical impedance and ultrasonic measurements in aluminum alloy 2024 that has been fatigued under high cycle conditions. While ultrasonic measurements can indicate fatigue-induced damage through changes in stiffness, the primary indicator is ultrasonic attenuation. We have used laser ultrasonic methods to investigate changes in ultrasonic attenuation since simultaneous measurement of longitudinal and shear properties provides opportunities to develop classification algorithms that can estimate the degree of damage. Electrical impedance measurements are sensitive to changes in the conductivity and permittivity of materials - both are affected by the microstructural damage processes related to fatigue. By employing spectral analysis of impedance over a range of frequencies, resonance peaks can be identified that directly reflect the damage state in the material. In order to compare the impedance and ultrasonic measurements for samples subjected to tension testing, we use processing and classification tools that are matched to the time-varying spectral nature of the measurements. Specifically, we process the measurements to extract time-frequency features and estimate stochastic variation properties to be used in robust classification algorithms. Results are presented for fatigue damage identification in aluminum lug joint specimens.

Original languageEnglish (US)
Title of host publicationHealth Monitoring of Structural and Biological Systems 2009
DOIs
StatePublished - Jun 15 2009
EventHealth Monitoring of Structural and Biological Systems 2009 - San Diego, CA, United States
Duration: Mar 9 2009Mar 12 2009

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7295
ISSN (Print)0277-786X

Other

OtherHealth Monitoring of Structural and Biological Systems 2009
CountryUnited States
CitySan Diego, CA
Period3/9/093/12/09

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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    Channels, L., Chakraborty, D., Butrym, B., Kovvali, N., Spicer, J., Papandreou-Suppappola, A., Afshari, M., Inman, D., & Chattopadhyay, A. (2009). A comparative study of fatigue damage sensing in aluminum alloys using electrical impedance and laser ultrasonic methods. In Health Monitoring of Structural and Biological Systems 2009 [72950Q] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7295). https://doi.org/10.1117/12.815980