Crack detection in metallic structures using piezoceramic sensors

This paper reports the application of piezoceramic sensors for crack detection in metallic structures. A rectangular aluminium plate with a crack initiated by spark erosion was used in a simple fatigue experiment. The plate was instrumented with piezoceramic devices bonded in a symmetrical configuration on both sides of the crack. One of the piezoceramics was used as an actuator and excited by a Gaussian white noise signal. The plate was subjected to static and dynamic tensile loading. The growing crack was monitored by the remaining piezoceramic sensors. The experimental data was analysed using a statistic based on the variance of wavelet coefficients, representing different orthogonal wavelet levels. The results show the potential of the piezoceramic sensors for structure-integrated automated damage detection systems in metallic structures.