Fast Fourier transform method for determining velocities of ultrasonic Rayleigh waves using a comb transducer

Area of Science:

• Materials Science
• Acoustics
• Non-Destructive Testing

Background:

• Ultrasonic Rayleigh waves are crucial for material characterization.
• Accurate velocity measurement is essential for NDT applications.
• Existing methods can be complex or require precise distance/time data.

Purpose of the Study:

• To develop a convenient and accurate method for determining ultrasonic Rayleigh wave velocities.
• To utilize comb transducers and frequency analysis for precise material property assessment.
• To validate the proposed method against established techniques.

Main Methods:

• Utilized a comb transducer to measure ultrasonic Rayleigh wave signals.
• Applied Fast Fourier Transformation (FFT) to convert time-domain signals to the frequency domain.
• Calculated wave velocities using the formula c_r = fl, where f is central frequency and l is transducer tooth spacing.

Main Results:

• The proposed method accurately determines Rayleigh wave velocities (2100-3400 m/s) in diverse materials.
• Experimental measurements demonstrated high precision due to stable central frequencies.
• Validation against the time-of-flight method showed relative errors consistently below 1%.

Conclusions:

• The comb transducer-based FFT method offers a precise and convenient approach for ultrasonic Rayleigh wave velocity determination.
• This technique simplifies experimental procedures by eliminating the need for propagation distance and time measurements.
• The high accuracy and precision make it suitable for material characterization and non-destructive testing.