المؤلفون: Garcia Macias E., Ubertini F.

المساهمون: Garcia Macias, E., Ubertini, F.

مصطلحات موضوعية: Ambient vibration testing, Automated Operational Modal Analysi, Seismic Interferometry, Structural Health Monitoring, Wave propagation

الوصف: Structural Health Monitoring (SHM) based upon Operational Modal Analysis (OMA) constitutes an increasingly mature and widespread technology in the conservation of historic structures. Such techniques, while proved effective for assessing the global integrity of structures, may fail at detecting local damage with little influence on the modal features of the system. In this context, the analysis of propagating waves throughout the structure features a synergistic approach to OMA with superior capabilities for data-driven damage identification. Although some promising results have been reported in the literature on the application of Seismic Interferometry to reinforced-concrete structures, works concerning the continuous monitoring of ambient vibrations in historic structures are virtually non-existent. In this light, this paper proposes the coupled application of automated OMA and Ambient Noise Deconvolution Interferometry for the full structural system identification of historic structures, and evaluates the advantages of this technology through a validation case study of the Sciri Tower in Perugia, Italy. A continuous vibration-based monitoring system deployed in the tower during three weeks allows us to assess the effectiveness of the proposed approach. The reported results demonstrate the robustness of the monitoring system for identifying environmental effects on the spatial distribution of wave velocities, and shed light into the dispersion relation of the tower.

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000537311500003; volume:215; firstpage:110615; journal:ENGINEERING STRUCTURES; http://hdl.handle.net/11391/1473928Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85084178080

الإتاحة: https://doi.org/10.1016/j.engstruct.2020.110615Test
http://hdl.handle.net/11391/1473928Test

المؤلفون: Garcia-Macias E., Ubertini F.

المساهمون: Garcia-Macias, E., Ubertini, F.

مصطلحات موضوعية: Damage identification, Masonry tower, Smart material, Structural Health Monitoring, Wave dispersion, Wave propagation

الوصف: The inherent vulnerability of masonry structures to seismic events makes Structural Health Monitoring of pivotal importance for the conservation of architectural heritage. In this regard, methods based on Operational Modal Analysis are becoming popular for damage identification. Nonetheless, these techniques may fail at detecting local damages with limited effects on the modal properties of the system. Recent studies report seismic interferometry to be a promising alternative for seismic damage identification of structures. This technique assesses the travelling times of propagating seismic waves between pairs of sensors, which are directly related to the local stiffness of the structure. Therefore, damageinduced degradation can be tracked through wave time delays. While some encouraging results have been reported on the application of acceleration-based seismic interferometry to reinforced-concrete structures, the number of works on masonry structures is far scarce. In this light, this paper is aimed at investigating the suitability of acceleration- and strainbased seismic interferometry for damage identification in historic masonry towers. To do so, an analytical layered Timoshenko beam model is devised for the wave propagation analysis of masonry towers under base motion. Parameter sensitivity analyses are first reported, with a special focus on the effects of dispersion upon system identification results. Secondly, a validation case study of a 41.6 m high masonry tower is presented. A realistic three-dimensional non-linear finite element model is built and subjected to seismic inputs causing increasing damage severities. The numerical results, used as pseudoexperimental data, demonstrate that it is possible to identify (detect, localize and quantify) earthquake-induced damages by wave propagation analysis of strain/acceleration records and inverse calibration of the proposed Timoshenko beam model. A particularly notable result is the possibility of detecting, localizing and, to some extent, quantifying ...

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000487013900022; volume:132; firstpage:380; lastpage:404; numberofpages:25; journal:MECHANICAL SYSTEMS AND SIGNAL PROCESSING; http://hdl.handle.net/11391/1453916Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85068526703; http://www.elsevier.com/inca/publications/store/6/2/2/9/1/2/index.httTest

الإتاحة: https://doi.org/10.1016/j.ymssp.2019.06.037Test
http://hdl.handle.net/11391/1453916Test
http://www.elsevier.com/inca/publications/store/6/2/2/9/1/2/index.httTest

المؤلفون: Pucci E., Saccomandi G., Vergori L.

المساهمون: Pucci, E., Saccomandi, G., Vergori, L.

مصطلحات موضوعية: Asymptotic analysi, Viscosity admissibility criterion for shock wave, Wave propagation in incompressible isotropic hyperelastic materials

الوصف: We study the propagation of linearly polarized transverse waves in a pre-strained incompressible isotropic elastic solid. Both finite and small-butfinite amplitude waves are examined. Irrespective of the magnitude of the wave amplitude, these waves may propagate only if the (unit) normal to the plane spanned by the directions of propagation and polarization is a principal direction of the left Cauchy–Green deformation tensor associated with the pre-strained state. A rigorous asymptotic analysis of the equations governing the propagation of waves of small but finite amplitude reveals that the time scale over which the nonlinear effects become significant depends on the direction along which the wave travels. Moreover, we design theoretically an experimental procedure to determine the Landau constants of the fourth-order weakly nonlinear theory of elasticity.

وصف الملف: ELETTRONICO

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/31293357; info:eu-repo/semantics/altIdentifier/wos/WOS:000473748700007; volume:475; issue:2226; firstpage:20180891; journal:PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. SERIES A; http://hdl.handle.net/11391/1456240Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85068254215; http://rspa.royalsocietypublishing.orgTest/

الإتاحة: https://doi.org/10.1098/rspa.2018.0891Test
http://hdl.handle.net/11391/1456240Test
http://rspa.royalsocietypublishing.orgTest/

المؤلفون: BURRASCANO, Pietro, RICCI, MARCO, Callegari, Sergio, Montisci, Augusto, Versaci, Mario

المساهمون: Burrascano, Pietro, Callegari, Sergio, Montisci, Augusto, Ricci, Marco, Versaci, Mario

مصطلحات موضوعية: non-destructive evaluation, non-destructive testing, ultrasonics, signal processing, wave propagation

الوصف: This book deals with a number of fundamental issues related to the practical implementation of ultrasonic NDT techniques in an industrial environment. The book discusses advanced academic research results and their application to industrial procedures. The text covers the choice and generation of the signals energizing the system to probe position optimization, from quality assessment evaluation to tomographic inversion. With a focus to deepen a number of fundamental aspects involved in the specific objective of designing and developing an ultrasonic imaging system for nondestructive testing, aimed to automatically classify the entire production of an industrial production line, targeted to the field of precision mechanics. The contents of this book is the result of the common effort of six University Research Groups that focused their research activities for two years on this specific objective, working in direct conjunction with primary industrial firms, in a research project funded by the Italian government as a Strategic Research Project.

وصف الملف: ELETTRONICO

العلاقة: info:eu-repo/semantics/altIdentifier/isbn/978-3-319-10565-9; info:eu-repo/semantics/altIdentifier/isbn/978-3-319-10566-6; http://hdl.handle.net/11391/1367347Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84943274591; http://www.springer.com/it/book/9783319105659#aboutBookTest

الإتاحة: https://doi.org/10.1007/978-3-319-10566-6Test
http://hdl.handle.net/11391/1367347Test
http://www.springer.com/it/book/9783319105659#aboutBookTest

المؤلفون: Zilberti L., Voyer D., Bottauscio O., Chiampi M., Scorretti R.

المساهمون: Zilberti, L., Voyer, D., Bottauscio, O., Chiampi, M., Scorretti, R.

مصطلحات موضوعية: Dosimetry, millimeter wave propagation

الوصف: This paper investigates the influence of electrical and thermal human tissue parameters on the heating of a body illuminated by a millimeter plane electromagnetic wave. A stochastic approach is considered with a three-layer model of the body: it is found that the parameters of skin play a major role.

العلاقة: volume:51; issue:3; firstpage:1; lastpage:4; numberofpages:4; journal:IEEE TRANSACTIONS ON MAGNETICS; https://hdl.handle.net/11391/1554981Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84928739326

الإتاحة: https://doi.org/10.1109/TMAG.2014.2363898Test
https://hdl.handle.net/11391/1554981Test

المؤلفون: Garcia Macias E., Kita A., Ubertini F.

المساهمون: Garcia Macias, E., Kita, A., Ubertini, F.

مصطلحات موضوعية: Ambient vibration testing, damage identification, seismic interferometry, structural health monitoring, wave propagation

الوصف: Conservation techniques within the framework of structural health monitoring, particularly through dynamic measurements and operational modal analysis, are becoming popular for condition-based maintenance and decision-making in historic structures. Nonetheless, while effective for giving insight into the overall behaviour of structures, these techniques may fail at detecting local damages with limited effects on the modal features of the system. In this regard, the analysis of propagating waves throughout the structure poses an attractive alternative for data-driven damage identification. Specifically, some encouraging results have been reported on the application of seismic interferometry to reinforced concrete structures, albeit the number of works concerning ambient vibrations is far scarce, and practically nonexistent in the realm of historic structures. In this light, this article explores the synergistic application of operational modal analysis and ambient noise deconvolution interferometry for the structural identification of historic structures through three different case studies, namely the Sciri Tower in Perugia, the Consoli Palace in Gubbio and the bell-tower of the Basilica of San Pietro in Perugia. The first case study represents a typical example of a masonry tower inserted into a building aggregate, while the second one constitutes a particular case of a monumental masonry palace. The presented results and discussion cover diverse aspects of the identification of wave velocities, signal processing strategies, effects of dispersion and robustness of the identification. Finally, the case study of the bell-tower of the Basilica of San Pietro illustrates the application of operational modal analysis and deconvolution interferometry for damage identification. To do so, two different ambient vibration tests conducted before and after the 2016 Central Italy seismic sequence are studied. The results show concentrated reductions in the wave velocities in the area of the belfry, which demonstrates that ...

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000491738000001; firstpage:147592171988145; journal:STRUCTURAL HEALTH MONITORING; http://hdl.handle.net/11391/1459425Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85074416696; http://shm.sagepub.comTest/

الإتاحة: https://doi.org/10.1177/1475921719881450Test
http://hdl.handle.net/11391/1459425Test
http://shm.sagepub.comTest/