Damage identification in a parabolic arch via orthogonal empirical mode decomposition

Localized damage in a parabolic arch is identified by combining a time-frequency vibration signals processing technique and modal-based properties. The approach is devised to detect and locate damaged areas in the structure from its free vibrations and relies on the comparison between information gathered for the undamaged and damaged states. The non-stationary acceleration data are decomposed by applying the orthogonal empirical mode decomposition to derive the orthogonal intrinsic mode functions. The latter provide a multi-frequency basis enabling to build ”pseudo-modes” based on which a new damage index is proposed. The performance of the devised approach is shown through pseudo-experimental tests on a damaged arch.