Parameter measurement of the cylindrically curved thin layer using low-frequency circumferential Lamb waves

Area of Science:

• Materials Science and Engineering
• Acoustics and Ultrasonics
• Solid Mechanics

Background:

• Characterizing thin layers with cylindrical curvature is crucial for various engineering applications.
• Traditional methods struggle with thin layers where wave reflections and modes overlap in time or space.
• Accurate determination of elastic constants, thickness, and radius is essential for performance prediction.

Purpose of the Study:

• To develop and validate a low-frequency circumferential Lamb wave method for characterizing cylindrically curved thin layers.
• To assess the sensitivity and accuracy of the proposed technique for determining layer parameters.
• To enable non-destructive evaluation of thin-walled curved structures.

Main Methods:

• Utilized low-frequency circumferential Lamb waves propagating along the curved surface of the thin layer.
• Measured the phase velocity of the Lamb waves.
• Employed a minimization of mean square error between theoretical and experimental phase velocities to estimate unknown parameters (elastic constants, thickness, radius).

Main Results:

• Successfully characterized cylindrically curved thin layers with an average relative error less than two percent in experimental measurements.
• Demonstrated the capability to measure layers with thicknesses down to ten percent of the longitudinal wavelength.
• Analyzed the sensitivity and accuracy of the technique with respect to different layer parameters.

Conclusions:

• The low-frequency circumferential Lamb wave method provides an accurate and sensitive approach for non-destructively characterizing curved thin layers.
• This technique overcomes limitations of traditional methods for thin and curved structures.
• The findings have significant implications for quality control and structural health monitoring in relevant industries.