PSI - Issue 62

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ Structural Integrity Procedia 00 (2022) 000 – 000

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Procedia Structural Integrity 62 (2024) 911–915

II Fabre Conference – Existing bridges, viaducts and tunnels: research, innovation and applications (FABRE24) HHT-based methodology for bridge's nonlinear response identification Fabrizio Scozzese * , Andrea Dall’Asta School of Architecture and Design, University of Camerino, Ascoli Piceno, Italy Abstract This work focuses on prestressed reinforced concrete bridges realized with post-tension of internal cables. The response of these structures in service is expected to be elastic but it can show some degree of nonlinearity due to tendons relaxation or critical event occurring on the pre-stressing system, conditions which are impossible to be detected unless specific accurate inspections are performed. In this study, a methodology is proposed to characterize the nonlinear behavior of these systems exploiting the bridge operational traffic conditions, in particular the input produced by the passage (for a limited time duration) of heavy trucks, which generate dynamic responses characterized by significant levels of non-stationarity and nonlinearity. In the present study, the abilities of the Hilbert-Huang Transform (HHT) in extracting the instantaneous properties of vibration of the bridge are investigated through some preliminary theoretical applications on simplified dynamic systems. © 2024 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 Scientific Board Members Keywords: Hilbert-Huang Transform; Damage detection; Bridges; post-tension cables; Empirical Mode Decomposition; frequency variation 1. Main text Post-tensioned reinforced concrete bridges are among the most diffused typologies built around the 70-80s in many country (Borzi et al. (2015), Minnucci et al. (2022), Poeta et al. (2023), Scozzese & Minnucci (2023)), and © 2024 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 Scientific Board Members

* Corresponding author. E-mail address: fabrizio.scozzese@unicam.it

2452-3216 © 2024 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 Scientific Board Member s

2452-3216 © 2024 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 Scientific Board Members 10.1016/j.prostr.2024.09.122