Angular-profile tuning of guided waves in hollow cylinders using a circumferential phased array.

Area of Science:

• Physics
• Acoustics
• Materials Science

Background:

• Nonaxisymmetric guided waves in hollow cylinders exhibit angular profiles sensitive to distance, frequency, and mode.
• Controlling these profiles typically requires altering wave parameters for single elements.
• Phased arrays offer a potential solution for dynamic angular profile manipulation.

Purpose of the Study:

• To implement angular-profile tuning of guided waves in hollow cylinders.
• To demonstrate the capability of circumferentially placed phased arrays for controlling guided wave propagation.
• To explore applications in nondestructive evaluation (NDE) for enhanced pipe inspection.

Main Methods:

• Utilizing partial loading elements within a circumferentially placed phased array.
• Generating nonaxisymmetric guided waves via individual array elements.
• Superposing contributions from array elements to achieve a controlled total angular profile.

Main Results:

• Demonstrated that the total angular profile is a superposition of individual element contributions.
• Showcased the ability to control and focus guided wave angular profiles at specific circumferential locations.
• Achieved focused guided wave beams for improved defect detection.

Conclusions:

• Angular-profile tuning using circumferential phased arrays provides precise control over guided wave beams.
• This technique enables effective circumferential scanning for NDE applications.
• The focused beams facilitate the detection of smaller defects in pipes.