PSI - Issue 84

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ScienceDirect

Procedia Structural Integrity 84 (2026) 223–230

© 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference Keywords: Effective Independence; Operational Modal Analysis; Optimal Sensor Placement; Strain Gauges; Strain Modal Analysis. Abstract Strain-based dynamic monitoring is an attractive alternative to conventional accelerometer-based approaches because strain mode shapes are inherently more sensitive to local damage. Optical Fiber Bragg Grating (FBG) sensors have demonstrated the feasibility of extracting strain modes under operational excitation in full-scale applications, though their widespread adoption remains constrained by interrogator cost and installation complexity. In this context, this work presents a full-scale demonstration of strain based Operational Modal Analysis (OMA) using resistive strain gauges (SGs) on a steel pedestrian footbridge. A low-cost data acquisition system has been implemented, and two ambient vibration tests (AVTs) have been conducted using two different sensor layouts optimized with the Effective Independence (Effi) algorithm. The identified strain modes have been benchmarked against accelerometer-based OMA results and finite element model (FEM) predictions. The consistent identification of three strain mode shapes supports the feasibility of the proposed methodology as a cost-effective alternative to FBG-based deployments for the dynamic characterization of steel civil structures. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Strain-Based Dynamic Identification of a Steel Footbridge with a Low-Cost Monitoring System Antonio S. López-Cuervo a *, Daniel Triana Camacho b , Filippo Ubertini b , Juan Chiachío a , Enrique García-Macías a a Department of Structural Mechanics and Hydraulic Engineering, University of Granada, Av. Fuentenueva sn, Granada, 18002, Spain b Department of Civil and Environmental Engineering, University of Perugia, Via G. Duranti 93, Perugia, 06125, Italy

* Corresponding author. E-mail address: antonioluis@ugr.es

2452-3216 © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference 10.1016/j.prostr.2026.06.030