Numerical modelling and experimental testing of vibration-based debonding quantification on tile panels

Interfacial debonding is recognized as the most critical failure mechanism in adhesively bonded tiling systems which may cause potential falling of tile panels. Several techniques have been well developed in this field to assess the tiling systems in terms of the existence of debonding. However, limited research has been found to be capable of quantifying the debonding. In addition, previous studies typically employed a one-excitation, one-detection approach with a large amount of testing points, and often targeted large debonding sizes. This research aims to fill the gaps by investigating the vibration responses of tile panels and identifying appropriate approaches for debonding quantification. It introduces a more efficient standardised one-excitation, multiple-detection method, reducing testing points required and extending the capability to smaller debonding sizes. Numerical simulation and experimental studies were conducted, and responses were collected and analysed in the frequency domain. Both benchmark-based and benchmark-free approaches were proposed with relevant quantification indicators correlated to debonding size. It was found that the natural frequency and energy within the lower frequency band are effective indicators of the debonding size when a benchmark is available for comparison. In the absence of benchmark, the correlation coefficient between different quadrants of the tile panels is capable of quantifying the debonding size. Additionally, the quadrant where the defect is most likely located can also be identified.