Simultaneous detection of muli-type damage in highway prefabricated bridges by nondestructive impact testing

Highway prefabricated bridges are widely used in medium and small-span systems, where bearings and lateral connections are the most damage-prone components. However, existing damage detection methodologies primarily focus on a single type component damage, which rarely address scenarios involving both bearings and lateral connections’ damage existing simultaneously. To address this limitation, this study proposes a practical and cost-effective methodology for simultaneous localisation and quantification of multi-type damage using nondestructive impact testing. Two novel benchmark-free damage localisation indicators are proposed: NVD (Normalised Virtual Deflection) for bearing damage and SSD (Spectral Similarity Difference) for lateral connection damage, both with strong sensitivity and clear physical meaning. By fusing NVD and SSD through the Levenberg-Marquardt algorithm, the method further achieves robust damage quantification function. Numerical simulations and model bridge experiment confirm the method’s high accuracy, strong anti-noise performance, and high sensitivity to damage type, location, or severity. By enabling the simultaneous detection of lateral connection and bearing damage for the first time, the developed method offers a promising solution for the comprehensive evaluation of highway prefabricated bridges in actual engineering.