PSI - Issue 64

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000–000 Available online at www.sciencedirect.com Procedia Structural Integrity 64 (2024) 724–731 Structural Integrity Procedia 00 (2023) 000–000

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SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Hybrid vibration testing for bridge modal system identification Ge-Wei Chen a , Xinghua Chen b , Piotr Omenzetter c,* a Central South University of Forestry and Technology, Changsha, China b China Three Gorges University, Yichang, China c The University of Aberdeen, Aberdeen, UK Abstract Output-only system identification of a large post-tensioned concrete bridge using hybrid excitation was conducted. To boost ambient excitations, dynamic forcing applied by two light-weight electrodynamic shakers was adopted for hybrid testing. The bridge modal characteristics were identified using three output-only identification methods: auto-regressive time series model, eigensystem realization algorithm with observer/Kalman identification and data-driven stochastic subspace identification method. The accuracy and efficacy of the system identification algorithms when applied to hybrid dynamic responses were investigated and benchmarked against the results obtained from pure ambient vibration testing. More modes were identified from the hybrid excitation data compared to using only ambient vibrations. The study demonstrated that using output-only identification algorithms on vibration responses produced by hybrid excitations can be used for extracting more accurate and reliable modal parameters with enhanced accuracy and reliability for large-scale structures due to enhanced excitation energy and better coverage of relevant frequency bands. Keywords: ambient vibration testing; hybrid vibration testing; output-only modal dentification; bridges 1. Introduction The evaluation of in-service bridge safety using measurements of structural actions and responses has become a feasible alternative to visual inspections or non-destructive testing. Particularly popular are vibration-based techniques often used to estimate the modal characteristics and calibrate finite element models (FEMs) to be further utilized for design validation, damage detection and performance assessment. The estimation of bridge modal parameters often relies on ambient vibration testing (AVT) and operational modal analysis (OMA) since large-scale structures can rarely SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Hybrid vibration testing for bridge modal system identification Ge-Wei Chen a , Xinghua Chen b , Piotr Omenzetter c,* a Central South University of Forestry and Technology, Changsha, China b China Three Gorges University, Yichang, China c The University of Aberdeen, Aberdeen, UK Abstract Output-only system identification of a large post-tensioned concrete bridge using hybrid excitation was conducted. To boost ambient excitations, dynamic forcing applied by two light-weight electrodynamic shakers was adopted for hybrid testing. The bridge modal characteristics were identified using three output-only identification methods: auto-regressive time series model, eigensystem realization algorithm with observer/Kalman identification and data-driven stochastic subspace identification method. The accuracy and efficacy of the system identification algorithms when applied to hybrid dynamic responses were investigated and benchmarked against the results obtained from pure ambient vibration testing. More modes were identified from the hybrid excitation data compared to using only ambient vibrations. The study demonstrated that using output-only identification algorithms on vibration responses produced by hybrid excitations can be used for extracting more accurate and reliable modal parameters with enhanced accuracy and reliability for large-scale structures due to enhanced excitation energy and better coverage of relevant frequency bands. Keywords: ambient vibration testing; hybrid vibration testing; output-only modal dentification; bridges 1. Introduction The evaluation of in-service bridge safety using measurements of structural actions and responses has become a feasible alternative to visual inspections or non-destructive testing. Particularly popular are vibration-based techniques often used to estimate the modal characteristics and calibrate finite element models (FEMs) to be further utilized for design validation, damage detection and performance assessment. The estimation of bridge modal parameters often relies on ambient vibration testing (AVT) and operational modal analysis (OMA) since large-scale structures can rarely © 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 SMAR 2024 Organizers

* Corresponding author. Tel.: +44-1224-272529 ; fax: +44-1224-272497. E-mail address: piotr.omenzetter@abdn.ac.uk

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 SMAR 2024 Organizers 10.1016/j.prostr.2024.09.337 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 SMAR 2024 Organizers 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 SMAR 2024 Organizers * Corresponding author. Tel.: +44-1224-272529 ; fax: +44-1224-272497. E-mail address: piotr.omenzetter@abdn.ac.uk