Open Access

ARTICLE

Output-only System Identification and Damage Assessment through Iterative Model Updating Techniques

by Leandro Fleck Fadel Miguel¹, Letícia Fleck Fadel Miguel²

1 UFSC, Florianópolis, SC, Brazil.
2 UFRGS, Porto Alegre, RS, Brazil.

Structural Durability & Health Monitoring 2012, 8(3), 249-270. https://doi.org/10.32604/sdhm.2012.008.249

Abstract

Model updating may be defined as an adjustment on the FE model through modal parameters experimentally obtained, in order to better represent its dynamic behavior. From this definition, structural health monitoring (SHM) methods can be considered closely related with these procedures, because it refers to the implementation of in situ non-destructive sensing and analysis of the dynamic system characteristics, which aims to detect changes that could indicate damage. Within this context, the present paper evaluates an iterative model updating approach when it is subjected to experimental vibration data. In addition, after getting the experimental adjusted model, a numerical damage detection procedure is also proposed. Since in ambient vibrations situations, it is only available the structural response, particular emphasis is given on output-only system identification. Two damage cases are created and dynamic tests are numerically simulated with a varying added measurement noise. In order to localize and quantify the damage, an index (damage detection index - DDI) is also proposed in this paper. It can be noticed that the obtained results were very accurate, and the proposed index DDI was able to correctly localize and quantify the damage in all situations, even considering an output only system identification procedure, noise presence and multiple damage case.

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Keywords

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