42. Damage Index Matrix: A Novel Damage Identification Method Using Hilbert-Huang Transformation

As novel construction materials become more economically and technically available throughout the globe, the structures become more complex. Therefore, an unexpected failure of these structures causes catastrophic economical and fatal losses. Over the past decades, a number of vibration based damage detection techniques have been developed to avoid unexpected failure in structures. These damage detection methods identify presence, location and magnitude of developed damage in the structure associated to change of modal properties such as natural frequency, mode shape and modal damping. An essential limitation of these techniques is that they are majorly sensitive to high intensity of damage only and do not correctly respond to minor to intermediate damage severities. This research proposed a novel damage detection methodology based on application of Hilbert-Huang Transform (HHT) on the acceleration response of the structure. HHT consists of Empirical Mode Decomposition followed by Hilbert Transform of the signal. The method develops a Damage Index Matrix for the structure by connecting energy index of the instrumented structural points. Viability of the proposed method is demonstrated through numerical examples and laboratory experiments. The method was able to locate both single and multiple damage scenarios in numerical models as well as laboratory experiment.