Damage Detection Using the Hilbert–Huang Transform
In this article, a new structural health monitoring and damage identification method is presented. The method developed here exploits a new time–frequency signal-processing analysis tool now commonly referred to as the empirical mode decomposition method coupled with the Hilbert–Huang transform. The empirical mode decomposition is a time-series analysis method that extracts a custom set of basis functions to describe the vibratory response of a system. The ability of the empirical mode decomposition to extract embedded oscillations, to reveal hidden reflections in the data and to provide a high-resolution energy–time–frequency spectrum is used to characterize guided Lamb wave interactions with various damaged regions. Case studies are used to illustrate the effectiveness of the empirical mode decomposition method and various damage detection metrics to infer damage in one- and two-dimensional structures.
