Statistical vibration-based damage localization on Saint-Nazaire Bridge mockup

International audienceThe characterization of damages from output-only vibration measurements is an important issue for Structural Health Monitoring (SHM), in particular for bridges under ambient excitation. In the last years, a multitude of methods has been proposed for vibration-based damage detection, lo-calization and quantification. In this work, a benchmark application for such methods is proposed, namely a 1/200 scale model of the Saint-Nazaire Bridge, which is a cable-stayed bridge spanning the Loire River near the river's mouth. The region of interest, the central metallic structure, measures 720 meters. The aim of the instrumentation is to assess the capability of damage assessment methods to assess a cable failure. The model is instrumented with ten accelerometers and excited by white noise. A damage localization method is applied to test the proposed setup, namely the statistical damage locating vector approach (S-SDDLV). With this method, vibration measurements from the (healthy) reference and damaged states of the structure are confronted to a finite element of the reference state. Damage indicators are provided for the different structural elements that are easy to compute, without updating the model parameters, and taking into account the intrinsic uncertainty of noisy measurements