Automating the Frequency Domain Decomposition Technique Using the Modal Assurance Criterion

Infrastructures are degrading rapidly, which necessitates the application of automated dynamic characterization in damage identification schemes. The Operational Modal Analysis (OMA) is an effective tool to process monitoring data of structural assets. In this study, the Frequency Domain Decomposition (FDD) technique is automated based on two different criteria, the Discrimination Factor (DF) and Modal Assurance Criterion (MAC). The recorded ambient vibration response of a cable-stayed bridge was used as input to the proposed method to extract its modal properties automatically. The method was also tested on a calibrated finite element model of the cable-stayed bridge for validation purposes. The optimal automation performance is achieved by establishing the best range of each criterion.