Informed assessment of structural health conditions of bridges based on free-vibration tests

A consolidated procedure for the evaluation of current structural health conditions in bridges consists in the comparison between estimated modal features from in-situ tests and numerical values. This strategy allows making informed decisions for existing bridge structures to ensure structural safety or serviceability. Free vibration tests are common in bridges monitoring since they allow a quick and cost-effective determination of dynamic information about the structure, using a sparse network of few sensors and avoid long-lasting monitoring campaigns. Exploiting an identification method based on a tuned version of Variational Mode Decomposition and an area-ratio based approach, modal parameters are determined from free vibration tests. This technique is applied to the dynamic identification of cables in a stay-cabled bridge assumed as case study: the obtained results prove reliability of the adopted method as a useful tool for objective dynamic identification purposes, with focus on the structural health conditions of bridges.