المؤلفون: Errico Fabrizio, De Rosa Sergio, Ichchou M., Franco Francesco, Bareille O.

المساهمون: Errico, Fabrizio, DE ROSA, Sergio, Ichchou, M., Franco, Francesco, Bareille, O.

مصطلحات موضوعية: Wave propagation, Dispersion curves, Modal analysis, Composite structures

الوصف: This work presents an approach for using a modal analysis on an equivalent finite cylindrical model, to predict the elastic waves in infinite, isotropic or composite, panels. In the description of the infinite paths, an analogy, between the classical topologies of a straight line and a circumference, is exploited and tested. Different aspects, concerning the wavemode duality and the discretization and the needed radii of curvature, are investigated to frame the problem and test the robustness of the methodology. The analysis presents a well conditioned problem and solution for any propagation wave angle by transforming the original problem into a simple modal analysis.

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000450384800006; volume:83; firstpage:80; lastpage:93; numberofpages:14; journal:WAVE MOTION; info:eu-repo/grantAgreement/EC/H2020/ID. 675441 (VIPER); http://hdl.handle.net/11588/720856Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85052316533

الإتاحة: https://doi.org/10.1016/j.wavemoti.2018.08.007Test
http://hdl.handle.net/11588/720856Test

المؤلفون: Memmolo V., Moll J., Nguyen D. H., Krozer V.

المساهمون: Memmolo, V., Moll, J., Nguyen, D. H., Krozer, V.

مصطلحات موضوعية: Electromagnetic, Measurement, Structural health monitoring, Wave propagation

الوصف: Ultra-wideband guided electromagnetic waves have been recently adopted to detect damage in structures. Transmission and reflection coefficients are indeed sensitive to any defect within the waveguide and can potentially warn the presence of hidden failures. Within this context, the paper shows a detection and localization approach for a structural health monitoring system based on elctromagnetic sensors permanently integrated with the structure to be monitored. A metallic plate is equipped with a dielectric waveguide patch attached to the structure's surface and a multi-input multi-output approach is adopted to interrogate the host component characterized by a reversible defect in different position. The findings show the sensitivity of transmission and reflection loss to the defect presence in between 3-20 GHz. Furthermore, an optimal frequency band beyond 12-15 GHz can be generally found. Based on wave spectrum changes, damage indicators result reliable means of detection. On top of that, they can be further elaborated to reconstruct and localize the defect. Both the amplitude and the phase of the signals are worth being investigated as detection and localization features.

العلاقة: info:eu-repo/semantics/altIdentifier/isbn/978-1-7281-7556-0; info:eu-repo/semantics/altIdentifier/wos/WOS:000713875300101; ispartofbook:2021 IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2021 - Proceedings; 8th IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2021; firstpage:552; lastpage:557; numberofpages:6; https://hdl.handle.net/11588/952251Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85114035912

الإتاحة: https://doi.org/10.1109/MetroAeroSpace51421.2021.9511755Test
https://hdl.handle.net/11588/952251Test

المؤلفون: Memmolo V., Moll J., Nguyen D. H., Krozer V., Holstein J., Kapoor R., Stindl J.

المساهمون: Memmolo, V., Moll, J., Nguyen, D. H., Krozer, V., Holstein, J., Kapoor, R., Stindl, J.

مصطلحات موضوعية: Electromagnetic, Measurement, Structural health monitoring, Wave propagation

الوصف: Guided electromagnetic wave propagation using ultrawideband signals is a barely new approach for damage detection. However, still many challenges are present, including the way to deal with the GHz domain signals and the physics behind the interaction phenomena enabled by any type of flaw. The present work proposes a feasibility analysis for a structural health monitoring system employing permanently integrated microwave sensors. This setup allows to interrogate the structure continuously using multiple transmitters and multiple receivers when the electromagnetic waveguide is established. To this end, a metallic plate is equipped with a dielectric waveguide patch attached to the structures' surface. To validate the detectability of damage, a reversible defect is modeled through removable bolts accessible from the other surface of the plate. The experiments are carried out considering different bottom holes at different spatial locations of the plate. In addition, concurrent measurements are adopted to characterize the noise level within the signal. The characteristic changes of electromagnetic wave signals are caught using a damage index approach returning whether the defect can be detected sensitively or not. Different coupling conditions are used to let the guided electromagnetic waves propagate and interact with underlaying structure. The results show that this approach can be adopted for damage detection with a reasonable signal to noise ratio, especially when the waveguide is well coupled. In addition, both transmission and reflection loss can be monitored reliably.

العلاقة: ispartofbook:Proceedings of 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2021; 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2021; https://hdl.handle.net/11588/952267Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85124132211

الإتاحة: https://hdl.handle.net/11588/952267Test

المؤلفون: Picariello G., Kouroussis G., van Parys L., Formisano A.

المساهمون: Picariello, G., Kouroussis, G., van Parys, L., Formisano, A.

مصطلحات موضوعية: Cultural building, Ground vibration, Ground wave propagation, Railway vibration, Track dynamics

الوصف: Due to the rapid development of urban railway networks, the problem of ground-borne vibration induced by railway traffic becomes important. For some buildings, these ground vibrations can induce cosmetic and structural damages and must be avoided according to the protection rules for old buildings. In the prediction of ground-borne vibration from railway systems, the amplification factor between each part of the building and the building foundation is not the only factor to take into account; the overall coupling between the building and the soil, as well as the nature of the excitation, remain important factors that must be mastered to reduce the vibration transmitted up through the buildings. The aim of this paper is to analyse the parameters that affects the vibration and to propose innovative solutions to help to reduce excessive vibration.

العلاقة: ispartofbook:"Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021; 27th International Congress on Sound and Vibration, ICSV 2021; https://hdl.handle.net/11588/902459Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85117495418

الإتاحة: https://hdl.handle.net/11588/902459Test

المؤلفون: Memmolo V., Moll J., Nguyen D. H., Krozer V.

المساهمون: Memmolo, V., Moll, J., Nguyen, D. H., Krozer, V.

مصطلحات موضوعية: Electromagnetic, Measurement, Structural health monitoring, Wave propagation

الوصف: Ultra-wideband guided electromagnetic waves have been recently adopted to detect damage in structures. Transmission and reflection coefficients are indeed sensitive to any defect within the waveguide and can potentially warn the presence of hidden failures. Within this context, the paper shows a detection and localization approach for a structural health monitoring system based on elctromagnetic sensors permanently integrated with the structure to be monitored. A metallic plate is equipped with a dielectric waveguide patch attached to the structure's surface and a multi-input multi-output approach is adopted to interrogate the host component characterized by a reversible defect in different position. The findings show the sensitivity of transmission and reflection loss to the defect presence in between 3-20 GHz. Furthermore, an optimal frequency band beyond 12-15 GHz can be generally found. Based on wave spectrum changes, damage indicators result reliable means of detection. On top of that, they can be further elaborated to reconstruct and localize the defect. Both the amplitude and the phase of the signals are worth being investigated as detection and localization features.

العلاقة: info:eu-repo/semantics/altIdentifier/isbn/978-1-7281-7556-0; info:eu-repo/semantics/altIdentifier/wos/WOS:000713875300101; ispartofbook:2021 IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2021 - Proceedings; 8th IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2021; firstpage:552; lastpage:557; numberofpages:6; https://hdl.handle.net/11588/952252Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85114035912

الإتاحة: https://doi.org/10.1109/MetroAeroSpace51421.2021.9511755Test
https://hdl.handle.net/11588/952252Test

المؤلفون: Memmolo V., Moll J.

المساهمون: Fromme, Paul, Memmolo, V., Moll, J.

مصطلحات موضوعية: Composite structure, Finite element modeling, Ice detection, Structural health monitoring, Wave propagation, Wave scattering

الوصف: Icing conditions are threatening for a variety of engineering applications. When accreting on the aircraft surface, ice may lead to catastrophic accidents while its deposition on turbine blades can overload the components reducing power and inducing damage. The first way to protect engineering constructions from icing issues deals with early detection of ice. Ultrasound has been demonstrated to be effective for detecting changes of the structure which it is propagating through. Guided waves interact with emerging flaw and discontinuity, including ice accreting on the surface. This paper introduces an experimental campaign carried out on composite structures subject to icing. The building up of planar ice onto surface structure is analysed. Furthermore, a parametric investigation is carried out by finite element modelling to look into the interaction between wave and ice while varying its dimension. Experimental findings demonstrate the ability of guided waves to detect ice layers accreting onto surface. In addition, the ice is likely to be identified from the scattering of guided waves resulting in different transmission and reflection characteristics. Instead, numerical outcomes show how the interaction of guided waves depends upon the thickness and length of the ice.

العلاقة: info:eu-repo/semantics/altIdentifier/isbn/9781510635395; info:eu-repo/semantics/altIdentifier/isbn/9781510635401; info:eu-repo/semantics/altIdentifier/wos/WOS:000624394000039; ispartofbook:Proceedings of SPIE - The International Society for Optical Engineering; Health Monitoring of Structural and Biological Systems IX 2020; volume:11381; serie:PROCEEDINGS OF SPIE, THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING; alleditors:Fromme, Paul; https://hdl.handle.net/11588/952268Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85087082880

الإتاحة: https://doi.org/10.1117/12.2572804Test
https://hdl.handle.net/11588/952268Test

المؤلفون: Pier Paolo G. Bruno, Aldo Vesnaver

المساهمون: Bruno, Pier Paolo G., Vesnaver, Aldo

مصطلحات موضوعية: This paper discusses a multivariate approach aimed at geophysical characterization of subsurface rocks for groundwater exploration in arid environments. We integrate several findings obtained from a single-source, single-sensor seismic profile with gravity data to detail the tectonic settings and characterize the subsurface, water-bearing formations of the Al Jaww Plain, one of the most important groundwater reserves of the United Arab Emirates. The seismic data have been acquired in the framework of the first EAGE Middle-East Bootcamp. Edge-detection techniques applied to the Bouguer anomaly map of the Al Jaww Plain allowed us to infer the presence of unreported ENE trending tectonic lineaments. The prestack depth migrated seismic image shows a clear and previously unreported east-verging thrust affecting seismic wave propagation and consistent with gravity data which was interpreted as an evidence of a detachment fold and thrust above the bottom of Fiqa Formation. Using the first-arrival picking from the common shot gathers, we tested a coupled tomographic inversion of P-wave velocity and Q factor which was aimed at achieving a qualitative characterization of rock petrophysical properties. K-means clustering was used to classify and map subsurface areas characterized by similar observations of P- and Q-wave velocity and therefore to outline shallow zones (<600 m) that are consistent with geophysical properties which are typical for water accumulations and within the reach of water groundwater exploration

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000613763000001; volume:8; firstpage:638; lastpage:657; numberofpages:20; journal:FRONTIERS IN EARTH SCIENCE; http://hdl.handle.net/11588/838963Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85100564176

الإتاحة: https://doi.org/10.3389/feart.2020.575019Test
http://hdl.handle.net/11588/838963Test

المؤلفون: Mohammad Hadi Rezaei, Naser Khaji, Rosa Di Maio, Antonio Emolo

المساهمون: Hadi Rezaei, Mohammad, Khaji, Naser, DI MAIO, Rosa, Emolo, Antonio

مصطلحات موضوعية: Computational seismology, Earthquake dynamics, Earthquake ground motions, Wave propagation, Dynamics and mechanics of faulting

الوصف: Specific barrier method (SBM) is a method used for ground motion generation from a finite fault surface. It is based on a regular distribution of rupturing circular subevents located on the fault plane and random arrival times of the waves generated by those cracks. This approach does not consider the whole rupture kinematics, that is the rupture propagation from the hypocentre to the subevents, and leaves parts of the fault unbroken (barriers). In this paper, we propose a modified version of the SBM for generation of synthetic ground motions from a fault surface. In this version, we modify the probability density function (PDF) for the arrival time of the waves coming from different parts of the fault in order to better account for the fault kinematics and the distance between fault point and receiver. In this way, we can simulate the middle part of the acceleration spectrum (i.e. between 0.1 and 7 Hz) with more accuracy. Moreover, a new arrangement for locating cracks throughout the fault plane is proposed to add flexibility to the model and enable it to make the part of the spectrum with frequency larger than 7 Hz more like what happens in nature. In such an arrangement, called geometry packing in this paper, the size of circles varies within a chosen specific allowable range, while the circles cover all over the fault plane without any overlaps. To validate the proposed modified SBM technique, the synthetic Fourier spectra are compared with recordings of the 2008 Mw6.9 Iwate–Miyagi (Japan) earthquake. Finally, we present some parametric studies to show how different features of the proposed PDFs affect the results from the SBM approach.

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000697668700006; volume:227; firstpage:76; lastpage:98; numberofpages:23; journal:GEOPHYSICAL JOURNAL INTERNATIONAL; http://hdl.handle.net/11588/854208Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85109030174; https://doi.org/10.1093/gji/ggab212Test

الإتاحة: https://doi.org/10.1093/gji/ggab212Test
http://hdl.handle.net/11588/854208Test

المؤلفون: Moll J., Simon J., Memmolo V.

المساهمون: Moll, J., Simon, J., Memmolo, V.

مصطلحات موضوعية: Aircraft structure, De-icing, Marine structure, Ultrasonic inspection, Wave propagation

الوصف: The paper presents an integrated active system for ice detection on composite plates with ultrasonic guided waves. The aim is to efficiently detect ice formation and growing on complex structures to ensure safety in transportation vehicles. Ice may lead to serious hazards and its early detection is crucial to avoid catastrophic events. In addition, structural health monitoring based on wave propagation benefits from its early detection preventing misleading interpretation of ultrasound signals. Guided wave propagation, likely adopted for damage monitoring in complex structures, can be likewise adopted to reveal the presence of the ice and characterize its dimension. Experimental tests have been carried out in this work to investigate the effect of an emerging ice layer on wave propagation using the pitch-catch approach. Different measurements have been carried out on a glass fiber composite panel integrated with light piezoelectric actuators. The icing condition is simulated using a climate chamber where water is used to trigger the ice formation. The ultrasonic data have been recorded with a dedicated acquisition system. Results show that reflections generated at the ice location are quite visible in the propagating waves indicating waves as ice sensitive. In addition waterfall diagram and RMS analysis show that ice significantly changes the signals. The outcomes and their post-processing analysis definitely prove the ability of guided waves to detect ice.

العلاقة: info:eu-repo/semantics/altIdentifier/isbn/978-1-7281-1344-9; ispartofbook:2019 IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2019 - Proceedings; 5th IEEE International Workshop on Metrology for AeroSpace, MetroAeroSpace 2019; firstpage:87; lastpage:91; numberofpages:5; https://hdl.handle.net/11588/952253Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85074402078

الإتاحة: https://doi.org/10.1109/MetroAeroSpace.2019.8869611Test
https://hdl.handle.net/11588/952253Test

المؤلفون: F. Errico, F. Franco, M. Ichchou, S. De Rosa, G. Petrone

المساهمون: Errico, F., Franco, F., Ichchou, M., De Rosa, S., Petrone, G.

مصطلحات موضوعية: wave finite element method, flow-induced vibrations, wave propagation, boundary layer excitation

الوصف: The present work investigates the effect on the flow-induced vibrations of the lay-up sequence of composite laminated axisymmetric structures, using an hybrid approach based on a wave finite element and a transfer matrix method. The structural vibrations, under deterministic distributed pressure loads, diffuse acoustic field and turbulent boundary layer excitations, are analysed and compared. A multi-scale approach is used for the dynamic analysis of fi nite structures, using an elementary periodic subsystem. Different flow regimes and shell curvatures are analysed and the computational efficiency is also discussed.

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000501565700002; volume:6; firstpage:463; lastpage:479; numberofpages:17; journal:ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE; http://hdl.handle.net/11588/779661Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85077881857

الإتاحة: https://doi.org/10.12989/aas.2019.6.6.463Test
http://hdl.handle.net/11588/779661Test