Related Experiment Video
Updated: Feb 16, 2026
08:40
Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing
Published on: February 11, 2016
12.1K
Material State Awareness for Composites Part I: Precursor Damage Analysis Using Ultrasonic Guided Coda Wave
Subir Patra1, Sourav Banerjee2
1Integrated Material Assessment and Predictive Simulation Laboratory, Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208, USA. spatra@email.sc.edu.
Materials (Basel, Switzerland)
|December 21, 2017
Summary
This study introduces an online ultrasonic technique using the coda wave to detect precursor damage in composite materials. This method quanties subtle material property degradation, improving structural health monitoring.
Area of Science:
- Materials Science
- Nondestructive Evaluation
- Composite Materials
Background:
- Accurate progressive failure models for composites require precursor damage detection, but current methods are insensitive.
- Precursor damages like matrix cracking and microcracks are often undetectable by conventional ultrasonic NDE/SHM systems.
- Existing low-frequency ultrasonic guided-wave systems (~100-~500 kHz) fail to capture early-stage composite degradation.
Purpose of the Study:
- To propose and validate an online ultrasonic technique for detecting and quantifying precursor damage in composite materials.
- To leverage the often-neglected coda part of guided wave signals for sensitive damage detection.
- To enhance the accuracy of structural health monitoring and failure modeling in composites.
Main Methods:
- An online ultrasonic technique utilizing the coda part of guided wave signals was developed.
- A modified Coda Wave Interferometry (CWI) technique, based on Taylor-series expansion, was employed.
- The CWI technique quantifies the stretch parameter to compensate for phase shifts caused by precursor damage.
- The method was applied to five woven composite-fiber-reinforced-laminate specimens.
Main Results:
- The proposed CWI technique successfully identified precursor events in composite specimens.
- Phase shifts in the coda wave packets were found to correlate with precursor damage.
- The identified precursor damage states were subsequently verified using Scanning Acoustic Microscopy (SAM) and optical microscopy.
- The technique demonstrates sensitivity to early-stage damage undetectable by conventional methods.
Conclusions:
- The developed online ultrasonic CWI technique effectively detects and quantifies precursor damage in composite materials.
- This method overcomes the limitations of traditional NDE/SHM systems in identifying subtle, early-stage degradation.
- The findings contribute to more accurate progressive failure modeling and improved structural health monitoring of composites.
