Analysis of Operational Modal Identification Techniques Performances and their Applicability for Damage Detection

Abstract

Operational modal identification techniques, also known asAmbientmodal orOutput Onlymodal, have been in recent years object of growing interest within several applications typical of civil, mechanical and aerospace engineering. In this paper, two of them, known as EFDD and SSI, are fully implemented by means of in-house codes and applied on a finite element beam model dynamic response time data, in order to evaluate their accuracy, focusing on the lowest system’s natural frequencies. Assessments of the techniques’ robustness to a disturbance in the random excitation, reliability when implementing on a small number of measurement channels and in localization and quantification of a given damage in multiple sites are also performed and presented.