Full wave field signal processing techniques for NDT of composites: A case study

Abstract

Non-destructive testing of composites using full wave field analysis of guided waves is illustrated for a CFRP aircraft panel with production defects. The full wave field is measured using 3D scanning laser Doppler vibrometry for broadband chirp excitation through one piezoelectric actuator. First, the A0 mode is extracted through mode filtering in the frequency-wavenumber domain. Next, the measured chirp response is converted to a narrowband burst response. At last, the local wavenumber map is constructed and evaluated. A debonding defect between stiffener and base plate is detected and confirmed by the ultrasonic C-scan time-of-flight map.