damage detection on thin walled structures with single frequency excitation and wavenumber filtering
Abstract »This paper describes the use of wavenumber filtering for damage detection with a single-frequency standing wave excitation on thin plate structures. Using a single, fixed frequency excitation from a mounted piezoelectric transducer, the full standing wave-field could be obtained using a Laser Doppler Vibrometer (LDV) with a mirror tilting device. After scanning, a wavenumber filtering is performed to determine certain wavenumber components, which could be used for damage detection. Mapping processes based on local wavenumber filtering is then carried out for damaged area visualization. Also introduced are the comparison of two methods for damage identification and visualization: the local wavenumber mapping and acoustic wavenumber spectroscopy. To demonstrate the proposed techniques, several experiments are performed on thin walled structures with several different types of damage, including corrosion in an aluminum plate and debonding on composite plates. The results demonstrate that the techniques are very effective in localizing damage with the potential for the improved damage detection capabilities with a high interrogation speed.