Exploring the performance limits of full-field acoustic wavenumber spectroscopy techniques for damage detection through numerical simulation

Using numerical models, we explored the performance of wavenumber spectroscopy techniques for estimating corrosion size and depth in several simulated aluminum plates. Through a series of simulations, we studied the effects of varying excitation frequency on spatial wavenumber resolution, corrosion depth and diameter effects on wavenumber estimation accuracy, and how overall plate thickness affects wavenumber estimation. We then added varying levels of white Gaussian noise to the simulated responses in order to study how measurement noise affects the estimates for a given plate thicknesses. We confirmed that inplane sizing resolution improves with increasing frequency, however, the relationship between frequency and accuracy of defect detection is highly dependent on the size of the corrosion and plate thickness, indicating that the common "resolution equals wavelength" guideline is insufficient and that all geometric properties must be considered together when determining the expected performance of a wavenumber imaging technique.