Piezoelectric 2-D Spiral Phased Array for Structural Health Monitoring of Thin Unidirectional Composite Panel

In this paper, a new 2-D phased array signal processing algorithm for structural health monitoring (SHM) of a thin unidirectional composite panel is presented. The new algorithm is modified by applying experimental wavenumber curves and wavefront curves to the same algorithm structure of the original 2-D phased array signal processing used to detect various damages in thin aluminum panels. The wavenumber curves and the wavefront curves were experimentally determined for the unidirectional composite panel. Piezoceramic based 2-D spiral phased array was used as a sensor array and multiple piezoceramic elements were used as off-centered actuators in the experiments. Damage detection in the unidirectional composite panel using guided Lamb wave (GLW) is demonstrated with the 2-D spiral phased array and the new signal processing algorithm.