A new method for plastic strain measurement with Rayleigh wave polarization

Area of Science:

• Materials Science
• Non-Destructive Testing
• Ultrasonic Testing

Background:

• Plastic strain measurement is crucial for material integrity assessment.
• Traditional methods may require contact or reference samples.
• Developing non-contact, reference-free techniques is highly desirable.

Purpose of the Study:

• To introduce a new non-contact, coupling-free ultrasound method for plastic strain measurement.
• To utilize electromagnetic acoustic transducers (EMATs) for measuring Rayleigh wave polarization (RWP).
• To establish an alternative ultrasonic testing technique with high spatial resolution.

Main Methods:

• Developed two specialized EMAT receivers to detect Rayleigh waves.
• Generated Rayleigh waves using an enhanced meander-line-coil EMAT.
• Measured the change in RWP caused by plastic strain in a specimen.

Main Results:

• Successfully measured the alteration in RWP due to applied plastic strain.
• Demonstrated that RWP changes correlate with surface plastic strain.
• Achieved accurate evaluation of plastic strain using the relative change in RWP.

Conclusions:

• The proposed EMAT-based method is a promising non-contact technique for plastic strain measurement.
• This approach offers a reference-free ultrasonic testing solution with high spatial resolution.
• The method provides accurate evaluation of surface plastic strain by monitoring RWP variations.