A Guided Wave Sensor Enabling Simultaneous Wavenumber-Frequency Analysis for Both Lamb and Shear-Horizontal Waves.

Area of Science:

• Materials Science
• Mechanical Engineering
• Nondestructive Testing

Background:

• Guided waves, including Lamb waves and shear horizontal (SH) waves, are crucial for structural health monitoring in plate-like structures.
• Existing sensors often struggle to detect both Lamb and SH waves and resolve their modal content (wavenumber-frequency spectrum).
• A unified sensor is needed to leverage the complementary benefits of both wave types for enhanced defect detection.

Purpose of the Study:

• To develop and demonstrate a novel sensor capable of detecting both Lamb and SH waves.
• To enable the measurement of the wavenumber-frequency spectrum for both wave types.
• To improve sensitivity to various discontinuity geometries in structural health monitoring.

Main Methods:

• Utilizing multi-element array sensor technology based on polyvinylidene difluoride (PVDF) film.
• Investigating the capability of the PVDF sensor to capture both Lamb and SH wave propagation characteristics.
• Analyzing the wavenumber-frequency spectrum obtained from the PVDF sensor data.

Main Results:

• Demonstrated that a PVDF-based multi-element array sensor can effectively detect both Lamb and SH waves.
• Successfully measured the wavenumber-frequency spectrum for both Lamb and SH waves using the developed sensor.
• The sensor shows potential for improved sensitivity to different defect types.

Conclusions:

• Polyvinylidene difluoride (PVDF) film serves as a viable basis for a multi-element array sensor for guided wave analysis.
• This sensor technology offers a promising solution for detecting both Lamb and SH waves and their modal content.
• The developed sensor advances structural health monitoring capabilities by providing comprehensive wave analysis.