A non-contact inspection method of tile debonding using tuned acoustic wave and laser doppler vibrometer

Abstract

The debonding of tiles from walls is currently a critical issue in modern cities. This study develops a non-contact acoustic approach integrating an effective numerical model for accurate inspection of tile debonding from a wall, with the aid of a directional sound source and a laser doppler vibrometer (LDV). Typical engineering tile debonding cases are characterised and analysed using the non-contact inspection method. Numerical modelling based on full-field modelling is performed to simulate and predict the inspection process. In both experiments and simulations, the acoustic wave with a sweeping frequency band is generated by the sound source and directed to the tiles. Activated vibration signals are captured at multiple points on the tile surface and then processed, and an out-of-surface velocity map of the tile is plotted to identify the debonding area, where good agreements between the numerical and experimental results can be seen. The results show that different shapes of the debonding areas under the tiles can be well detected, proving the effectiveness of the method.