Model–Based Methods of Damage Identification of Structures Under Seismic Excitation: Fid-Bau Portal

Model–Based Methods of Damage Identification of Structures Under Seismic Excitation

De Roeck, Guido

Abstract Vibration-based Structural Identification has become an increasingly popular experimental technique, e.g. for model calibration, control of structural behavior during construction, assessment of the efficiency of structural repair, … Main breakthrough was the development of operational modal analysis (OMA), avoiding the use of artificial vibration sources. Vibration-based Structural Health Monitoring is based on the principle that modal parameters of a structure are stiffness dependent. Changes in natural frequencies, damping ratios, mode shapes or combinations can therefore be used as features to detect and to identify damage. Non model-based methods try to identify damage from a comparison of pure measurements (or features directly derived from them) before and after a seismic event without relying on a (numerical) model. In most cases only the first (alarm) level of damage can be reached. The advantage of model-based methods is that they can go further in the damage identification process. They intend to localize and to quantify the damage. Disadvantage is the need to construct a reliable model. Mostly, linear models are used representing the quasi-linear state at small ambient vibrations before and after an earthquake, although there is an interest to use non-linear models for simulating the structural behavior during the earthquake.