STRUCTURAL DAMAGE IDENTIFICATION OF MUNICIPAL BRIDGES USING STRAIN FREQUENCY RESPONSE FUNCTION

A method for the localization and assessment of damage is presented in this study. The method is based on the use of Strain Frequency Response Function (SFRF) data sensitivities to changes in Young's modulus. With these sensitivities, differences in the dynamical behavior of the structure in its undamaged and damaged conditions can be translated into damage information. Numerically generated data, from a simple-supported plane, are used for better demonstration. Results illustrate that the SFRF curvature ratio change is sensitive to damage than three of the most referenced methods on literature, modal shape, modal strain and FRF curvature. The presented method is simple and robust in locating single or multiple damages as well as identifying damage severity for its less of sensitivity to the measurement errors, however, it is influenced by the frequency range to some extent.