PSI - Issue 52

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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 52 (2024) 418–423

© 2023 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 Professor Ferri Aliabadi Abstract Structural health monitoring based on ultrasonic guided waves is widely spreading attention in diagnosis and prognosis of engineered parts. Plate-like structures, such as those used in the aerospace sector, are often characterised by a variety of geometric features, either stiffeners or cross-sectional variations, which can affect the guided wave propagation mechanisms, complicating the measurements analysis. An in-depth knowledge of the phenomena involved in the interaction between guided waves and discontinuities is required to extract the key damage-related features from the collected signals. In this paper, the effects of a variable thickness on guided wave propagation are numerically investigated. Different finite element modelling techniques are proposed and compared to efficiently reproduce the geometric discontinuity. The 0-order fundamental modes excited and sensed by an array of piezoelectric transducers are considered; the group velocities are thus calculated and compared to prove the effectiveness of the approaches. © 2023 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 Professor Ferri Aliabadi Keywords: structural health monitoring; ultrasonic guided waves; composites; geometry discontinuity 1. Introduction The capability to inspect large areas [1] made ultrasonic guided waves (UGWs) one of the main tools used in structural health monitoring (SHM) for damage detection intents. UGWs propagate in two sets of modes, longitudinal or symmetrical (S i ) and shear or anti-symmetrical (A i ), generated by a family of waves whose motion is respectively symmetrical and anti-symmetrical with respect to the mean plane of the plate they propagate through. For both sets of modes there are an infinite number of orders, but the ones that deserve particular attention are the zero-order modes (S 0 and A 0 ) because they are present over the entire frequency spectrum, and in most practical 2452-3216 © 2023 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 Professor Ferri Aliabadi Fracture, Damage and Structural Health Monitoring FE modelling techniques for the simulation of guided waves in plates with variable thickness Donato Perfetto a,* , Claudio Pezzella b , Vincenzo Fierro b , Nima Rezazadeh a , Antonio Polverino a , Giuseppe Lamanna a a University of Campania Luigi Vanvitelli, Department of Engineering – via Roma 29, 81031 Aversa (Italy) b Mare Group – via Ex Aeroporto, 80038 Pomigliano d’Arco (Italy) Abstract Structural health monitoring based on ultrasonic guided waves is widely spreading attention in diagnosis and prognosis of engineered parts. Plate-like structures, such as those used in the aerospace sector, are often characterised by a variety of geometric features, either stiffeners or cross-sectional variations, which can affect the guided wave propagation mechanisms, complicating the measurements analysis. An in-depth knowledge of the phenomena involved in the interaction between guided waves and discontinuities is required to extract the key damage-related features from the collected signals. In this paper, the effects of a variable thickness on guided wave propagation are numerically investigated. Different finite element modelling techniques are proposed and compared to efficiently reproduce the geometric discontinuity. The 0-order fundamental modes excited and sensed by an array of piezoelectric transducers are considered; the group velocities are thus calculated and compared to prove the effectiveness of the approaches. © 2023 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 Professor Ferri Aliabadi Keywords: structural health monitoring; ultrasonic guided waves; composites; geometry discontinuity 1. Introduction The capability to inspect large areas [1] made ultrasonic guided waves (UGWs) one of the main tools used in structural health monitoring (SHM) for damage detection intents. UGWs propagate in two sets of modes, longitudinal or symmetrical (S i ) and shear or anti-symmetrical (A i ), generated by a family of waves whose motion is respectively symmetrical and anti-symmetrical with respect to the mean plane of the plate they propagate through. For both sets of modes there are an infinite number of orders, but the ones that deserve particular attention are the zero-order modes (S 0 and A 0 ) because they are present over the entire frequency spectrum, and in most practical 2452-3216 © 2023 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 Professor Ferri Aliabadi Fracture, Damage and Structural Health Monitoring FE modelling techniques for the simulation of guided waves in plates with variable thickness Donato Perfetto a,* , Claudio Pezzella b , Vincenzo Fierro b , Nima Rezazadeh a , Antonio Polverino a , Giuseppe Lamanna a a University of Campania Luigi Vanvitelli, Department of Engineering – via Roma 29, 81031 Aversa (Italy) b Mare Group – via Ex Aeroporto, 80038 Pomigliano d’Arco (Italy)

2452-3216 © 2023 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 Professor Ferri Aliabadi 10.1016/j.prostr.2023.12.042