Using Electromagnetic Acoustic Transducers (EMAT) To Detect Wheel Cracks

Initial test results were promising in the testing of an off-the-shelf electromagnetic acoustic transducer’s (EMAT) ability to detect subsurface wheel cracks.

Comparison of EMAT with Piezoelectric-based ultrasound generation

TTCI engineers and scientists have conducted laboratory testing of EMAT technology as a viable method for detecting defects in railcar wheels. Researchers utilized conventional ultrasonic testing to verify results from EMAT assessment of the wheels.

A-Scan signal for sub-surface cracks underneath the wheel tread.

TTCI researchers found that alternative sensor configurations and algorithms will need to be implemented to enhance signal quality and detection accuracy. This initial testing period does indicate that EMAT technology can be adapted to aid in the advancement of wheel inspection capabilities and enable high-speed inspections without need for couplant required for ultrasound inspection. TTCI is continuing work with the EMAT supplier to facilitate the development and deployment of this application of EMAT technology in wheel defect detection.

For more detail on this Association of American Railroads Strategic Research Initiatives program study, read more in the full article at Railway Age.

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About the author

Anish Poudel, Ph.D.
Principal Investigator II –
Non-destructive Evaluation (NDE)






Dr. Anish Poudel brings over a decade of distinguished experience in NDE and presently serves on the board of the American Society of Nondestructive Testing (ASNT).

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