Innovative wireless sensing for modal analysis and damage modeling of Petőfi Bridge

• The wireless sensor system offers a cost-effective and accurate solution for monitoring bridge structures. • Finite element modeling of the bridge agreed with field measurements and allowed for the exploration of various damage scenarios and their likely expression in the monitoring system. • Displacement Influence Lines (DILs) provide a reliable method for detecting potential damage in truss bridges. • Monitoring vertical displacement is particularly valuable for identifying localized damage in load-bearing members. • Changes in modal frequency are sensitive indicators of structural stiffness variations. The historic Petőfi Bridge (1933), a steel truss structure in Győr, Hungary, exemplifies the vulnerability of truss-type bridges to both local and total collapse. This study introduces an innovative, low-cost, accurate, and scalable wireless sensing system (WSS) for Structural Health Monitoring (SHM), utilizing the Petőfi Bridge as a case study. The research details the architecture and workflow of the system, with experimental validations confirming the accuracy of measured acceleration responses. The main natural frequencies of the bridge were estimated by processing the collected data, showing a strong correlation with reference values obtained through conventional wired systems. A calibrated high-fidelity finite element model analyzed the sensitivity of bridge damage detection indicators. The study explores variations in vertical displacement, and modal frequencies, and validates an approach based on displacement influence lines (DILs). The findings indicate the varying efficacy of these indicators in detecting structural damage, providing critical insights for advancing SHM practices.