Explaining operational modal analysis with data from an arch bridge

Abstract

a b s t r a c tThis tutorial paper aims to introduce the topic of operational modal analysis to nonspecialists on the subject. First of all, it is stressed the relevance of this experimental technique particularly in the assessment of important civil infrastructure. Then, after a synthesis of required theoretical background, three of the most powerful algorithms for output-only modal identification are presented. The several steps of these identification procedures are illustrated with the processing of data collected on a concrete arch bridge with a span of 280 m. As the use of operational modal analysis in the context of structural health monitoring is a subject under active research, this theme is also introduced and briefly exemplified with data continuously recorded at the same bridge.

Statistically Filtering Data for Operational Modal Analysis under Ambient Vibration in Structural Health Monitoring Systems

“…Popular approaches include frequency domain decomposition (FDD), covariance/data driven stochastic subspace identification (SSI-COV/-DATA), poly-least squares complex frequency domain (p-LSCF), maximum likelihood (ML) identification, and instrumental variable (IV) method etc. [8].…”

One Year of Continuous Dynamic Monitoring of a Wind Turbine. Structural Integrity and Fatigue Assessment

“…The modal identification of large structures excited by operational conditions, an approach usually named as Operational Modal Analysis (OMA), is a technique widely used in several applications [4]. Some examples of implementation of monitoring systems based on OMA in wind turbines are presented in [5,6].…”

“…The system is based on the continuous tracking of modal properties of the structure (frequency values, modal damping ratios and mode shapes), identified during the different operating conditions of a wind turbine. The strategy adopted for the monitoring system has already proved to be suitable to be installed both in onshore and offshore wind turbines [3].The modal identification of large structures excited by operational conditions, an approach usually named as Operational Modal Analysis (OMA), is a technique widely used in several applications [4]. Some examples of implementation of monitoring systems based on OMA in wind turbines are presented in [5,6].…”

Automated modal tracking and fatigue assessment of a wind turbine based on continuous dynamic monitoring

“…damage) and estimating the fatigue damage condition of the wind turbine. The monitoring system is based on Operational Modal Analysis (OMA) techniques [1], in which the modal properties of the structure (natural frequencies, modal damping ratios and mode shapes) are continuously tracked over the different operating conditions of the wind turbine. This strategy has already proven to be suitable to be installed both in onshore and offshore [2].…”