Optimization of Nonlinear Lamb Wave Detection System Parameters in CFRP Laminates.

Area of Science:

• Materials Science
• Nondestructive Testing
• Aerospace Engineering

Background:

• Carbon fiber reinforced polymer (CFRP) laminates are critical aerospace materials requiring robust safety assessments.
• Nondestructive testing (NDT) methods, particularly nonlinear Lamb wave testing, are essential for detecting damage in CFRPs.
• Ensuring aircraft safety necessitates improved accuracy in NDT for CFRP laminate integrity.

Purpose of the Study:

• To enhance the accuracy of nonlinear Lamb wave nondestructive testing for CFRP laminates.
• To optimize the parameters of the nonlinear ultrasonic detection system for improved damage assessment.
• To provide a validated methodology for reliable CFRP damage evaluation.

Main Methods:

• Performed single-factor experiments varying cycle number, output level, and amplifier gain.
• Utilized regression analysis on fundamental (A1) and second harmonic (A2) wave amplitudes.
• Developed and verified two response surface surrogate models using ANOVA and statistical analysis.

Main Results:

• Identified cycle number, output level, and gain as significant factors influencing A1 and A2.
• Established optimal detection system parameters: eight cycles, output level of 42, and 32 dB gain.
• Demonstrated high operational stability, accuracy, and reliability of the optimized system.

Conclusions:

• The optimized nonlinear ultrasonic detection system provides accurate and reliable assessment of CFRP laminate damage.
• This approach offers scientific guidance for improving NDT accuracy in aerospace applications.
• Validated response surface models are effective for optimizing NDT system parameters.