Delamination Localization in CFRP Laminates Using One-Way Mixing of Ultrasonic Guided Waves.

Area of Science:

• Materials Science
• Mechanical Engineering
• Non-destructive Testing

Background:

• Carbon fiber-reinforced polymer (CFRP) laminates are vital in aerospace but susceptible to invisible delamination.
• Early delamination detection is critical to prevent catastrophic failures in aircraft structures.
• Nonlinear ultrasonic guided waves offer high sensitivity for detecting such defects.

Purpose of the Study:

• To investigate the generation mechanism of one-way ultrasonic mixing in CFRP laminates.
• To analyze the interaction of one-way mixing with delamination.
• To develop a precise delamination localization method for CFRP structures.

Main Methods:

• Finite element simulation of A0 and S0 modes in CFRP laminates.
• Utilizing pulse-inversion techniques and 2D fast Fourier transforms.
• Employing the normalized acoustic nonlinearity parameter (χ') and time delays for localization.

Main Results:

• Successfully simulated one-way mixing of ultrasonic guided waves in CFRP.
• Determined modes and propagation directions of sum and difference frequency components.
• Precisely localized simulated delamination using the one-way mixing technique.

Conclusions:

• One-way ultrasonic mixing is a promising method for delamination detection in CFRP.
• This technique enables simultaneous excitation and reception for precise defect localization.
• The study provides a foundation for inspecting buried structures and enhancing aircraft safety.