Analysis of Distributed Sparse Array Configurations for Guided Wave Imaging Applications

Permanently attached, distributed sparse arrays of piezoelectric transducers have been proposed as a cost-effective solution for rapid interrogation of large, plate-like structures for structural health monitoring. Many proposed methods using these arrays rely on guided wave imaging techniques to interpret and graphically display information for damage detection and localization. Guided wave imaging algorithms, however, contain imaging artifacts that are due to reflections from boundaries and other structural features, even in a noise-free environment. The magnitude relationship between pixel values corresponding to actual damage and imaging artifacts is dependent on a number of variables, including imaging algorithm, number and location of transducers in the array, location and scattering behavior of damage, and structural geometry. This study proposes a metric to characterize the imaging performance of distributed sparse array systems and utilizes numerical simulations to analyze the impact of damage location, imaging algorithm, and physical array configuration on performance in the context of a single flaw in a rectangular aluminum plate.