A hybrid method based upon nonlinear Lamb wave response for locating a delamination in composite laminates

Area of Science:

• Materials Science
• Mechanical Engineering
• Non-Destructive Testing

Background:

• Composite laminates are susceptible to delamination, a critical failure mode.
• Existing Lamb wave methods often require baseline data from pristine materials, limiting practical application.
• Nonlinear Lamb wave responses, specifically higher harmonics, indicate the presence of damage.

Purpose of the Study:

• To introduce a hybrid nonlinear Lamb wave method for delamination detection.
• To apply the method for locating Barely Visible Impact Damage (BVID) in Carbon Fiber Reinforced Polymer (CFRP) laminates.
• To develop a baseline-free technique for damage assessment.

Main Methods:

• A hybrid approach combining time and frequency domain analysis of nonlinear Lamb wave responses.
• Utilizing spectral information (higher harmonics) and temporal response data.
• Formulation and experimental application to CFRP laminates with impact-induced delamination.

Main Results:

• The proposed hybrid method successfully locates delamination in CFRP laminates.
• The method effectively identifies BVID-induced damage.
• Demonstrated baseline-free capability, eliminating the need for pristine specimen data.

Conclusions:

• The hybrid nonlinear Lamb wave method offers a robust solution for delamination detection in composites.
• This technique provides accurate damage localization without prior reference data.
• The method shows significant potential for structural health monitoring of composite materials.