Multi-frequency localized wave energy for delamination identification using laser ultrasonic guided wave

Area of Science:

• Materials Science
• Non-Destructive Testing
• Acoustics

Background:

• Delamination is a critical failure mode in multilayered structures.
• Guided wave-based methods are sensitive to delamination defects.
• Multi-frequency approaches are necessary for comprehensive detection.

Purpose of the Study:

• To develop and validate a multi-frequency localized wave energy algorithm for delamination identification.
• To investigate the application of laser ultrasonic guided waves for delamination detection.
• To analyze the influence of delamination on wave energy distribution.

Main Methods:

• Utilizing laser ultrasonic guided waves to generate and detect acoustic waves.
• Developing a multi-frequency localized wave energy algorithm based on wavenumber components.
• Analyzing acoustic energy redistribution caused by delamination-induced mode conversion and scattering.
• Validating the algorithm through simulations and experiments on composite plate specimens.

Main Results:

• The multi-frequency localized wave energy algorithm effectively identifies delamination.
• Experimental results demonstrated reduced noise and clearer delamination profiles.
• The method showed distinct responses for medial and non-medial delamination types.
• Dispersion curve analysis informed the selection of critical parameters for identification.

Conclusions:

• The multi-frequency localized wave energy method is a viable technique for delamination identification in composite structures.
• Laser ultrasonic guided waves combined with this algorithm offer enhanced defect detection capabilities.
• Proper frequency selection and filter threshold are crucial for accurate delamination assessment.