Robust and baseline-free defect detection in aircraft CFRP components using full-field guided wave analysis

Non-destructive testing of composites using full 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 sweep excitation through one piezoelectric actuator. This wave field is analyzed for signs of damages using four different approaches. First, the broadband vibrational response is investigated for local defect resonance behavior at specific frequencies. Next, the band power is calculated, providing information on local vibrational energy of the structure. The broadband sweep response is converted to a narrowband A0 burst response by proper filtering in wavenumber-frequency domain. The converted signals are then used as input for weighted root mean square velocity calculation and local wavenumber estimation. For each of the four damage detection techniques, the damage detection performance is discussed