Instantaneous baseline structural damage detection using a miniaturized piezoelectric guided waves system

In recent years, new Structural Health Monitoring (SHM) methodologies with a concept of "instantaneous baseline damage detection" are being developed by many researchers since it has been found that the most of SHM technologies are too vulnerable to environmental and/or operational variations. In this context, this paper presents online instantaneous baseline structural damage detection using a low cost and low power, in-situ piezoelectric guided waves-SHM system. Firstly, four small, low cost and light weight smart Piezoelectric Ceramic (PZT) patches are surface-mounted and assumed to have the same bonding conditions to detect structural defects on an aluminum plate. Then, a miniaturized low power guided waves-SHM system with a Digital Signal Processing (DSP) module is employed for signal generation/excitation, signal sensing, and data processing. The instantaneous baseline damage detection based on Wavelet Transform (WT) and Cross Correlation (CC) analysis is carried out on the DSP module. Finally, effects of Lamb waves due to artificial 'cut-damage' at different locations are investigated using both "pitch-catch" and "pulse-echo" wave propagation schemes. Conclusively, this study shows a good potential for online and in-situ crack monitoring on panel structures such as an aircraft wing.