Advances in Cultural Heritage Studies : Year 2020 : Contributions of the European Students’ Association for Cultural Heritage

The announcement of the creation of a European Year of Cultural Heritage (year 2018) – by the Decision 2017/864 of the European Parliament – encouraged the creation, in 2017, of the European Students’ Association for Cultural Heritage (ESACH). ESACH has become the first still-growing interdisciplinary and cross- -generational network in the field. Currently brings together young researchers and researchers at early stages of their careers, in the fields of culture and heritage, from all kinds of academic disciplines and is made up of members from various European universities and research centres (see www.esach.org). Within the network, the main questions are: How do we engage with the past elements of our culture(s)? How and why do we protect culture as a genuine element of a contemporary cultural system? What do younger generations state as heritage and what ways do they see to safeguard and experience it? ESACH stands up for a participatory way of involvement and is eager to take part in the cultural discourse at European and national levels. Since ESACHS’ foundation, the Portuguese publisher Mazu Press (www.mazupress.com) has been associated with the initiatives of the Portuguese branch of ESACH based in Lisbon (Sharing Heritage Lisbon), firstly with the promotion actions and then with the publication of the book “New Perspectives in Interdisciplinary Cultural Heritage Studies. Contributions of the European Students’ Association for Cultural Heritage in the European Year of Cultural Heritage 2018”. In this atypical Covid-19 pandemic year, Mazu Press again invited ESACH to join the renewed idea of “unifying through Cultural Heritage”, creating the opportunity for all to associate their efforts to this volume of “Advances in Cultural Heritage Studies, Year 2020”. Until now, ESACH members have been given the opportunity to contribute their ideas in several European events organized by the respective stakeholders, such as the Genoa Meeting, in October 2019, which had the cultural, logistic and financial support of the University of Genoa and foremost the PhD Course in Study and Enhancement of the Historical, Artistic-Architectural and Environmental Heritage. This book brings together twenty chapters by twenty four authors from Canada, Greece, Ireland, Italy, Poland, Portugal, Slovakia, Spain and Turkey. This sharing of knowledge, culture and heritage studies, through various disciplines, shows the richness – advances and new perspectives – generated by the common passion for cultural heritage.Mazutech R&D; Università di Genova / Scuola di Scienze Umanistiche / Dottorato in Studio e Valorizzazione del Patrimonio Storico, Artistico-Architettonico e Ambientaleinfo:eu-repo/semantics/publishedVersio

A Multidisciplinary Strategy for the Inspection of Historical Metallic Tie-Rods: The Milan Cathedral Case Study

A reliable assessment of historical metallic tie-rods requires both the estimation of actual tensile load and the identification of dominant defects. Despite high defectiveness resulting from traditional metalworking techniques, so far the latter aspect has not been duly addressed in the literature. In this article, several methodologies are discussed aimed at integrating the usual inspection practice. All studies were performed on the tie-rods of Milan Cathedral. Metallurgical analyses allowed to recognize the main features of the material. Mechanical characterization in the perspective of Elasto-Plastic Fracture Mechanics (EPFM) indicated the conditions for crack propagation. Several Non-Destructive Techniques (NDTs) commonly used in Mechanical Engineering (i.e., guided waves, eddy currents, pulsed active thermography) were examined and adapted to this unconventional application. Based on the combination of all the mentioned methods, a multidisciplinary procedure was defined, which allows the evaluation of the crack significance with reference to the estimated working stress

A feasibility analysis on the application of eddy current testing to the detection of the most detrimental defects in historical metallic tie-rods

Historical metallic tie-rods have a very important structural role in buildings characterized by arches and vaults because they balance the horizontal thrusts, avoiding the overturning of vertical supports. Nowadays, no information can be found in the literature about the non-destructive detection of possible defects in historical tie-rods and their effects on the in-service structural integrity. On the other hand, many Non-Destructive Techniques are commonly used to inspect modern metallic components and structures, but their viability for cultural heritage is still to be assessed. In this paper, the application of eddy current testing to the historical metallic tie-rods of the Milan cathedral (Italy) is evaluated, discussed and adapted. The considered historical structures are characterized by a very heterogeneous material, irregular surface geometry and high inherent defectiveness. Recently, in-service failures showed the most detrimental flaws in tie-rods consist of handmade straight scarf forged welds. A first experimental eddy current testing approach, based on off-the-shelf high and low frequency probes, was performed. Results were partially unsatisfactory and showed the challenge is not the maximization of sensitivity and spatial resolution, as in typical modern applications, but their suitable minimization. Consequently, a customized eddy current testing technique, based on a novel low frequency probe, was designed and optimized. Its performance was evaluated by numerical simulations as well as by experimental testing. Based on the satisfactory achievements, the customized eddy current testing technique was applied on site on seven tie-rods. The most significant discontinuities could be effectively detected

Catene storiche in ferro battuto - Innovazione nella diagnostica per la ricerca di difetti

Le indagini diagnostiche sulle catene metalliche negli edifici storici, oltre alla stima della tensione mediante prove dinamiche, richiedono una valutazione della capacità resistente, che spesso è condizionata dalla presenza di difetti connaturati alle tecniche tradizionali di lavorazione dei metalli. Al tal fine, l'esame visivo può essere integrato mediante un opportuno adattamento di alcuni metodi di indagine consolidati nell'ambito dell'Ingegneria Meccanica. In questo studio sono state verificate le potenzialità delle tecniche delle onde guidate, delle correnti parassite e della termografia attiva pulsata, al fine di identificare i soli difetti dominanti presenti in elementi lineari in ferro battuto. Il lavoro, focalizzato sulle catene del Duomo di Milano, è stato corredato dall'analisi metallurgica e dalla caratterizzazione della tenacità del materiale, in vista di una successiva valutazione della stabilità di eventuali cricche significative. Sulla base della combinazione dei metodi citati, è stata quindi definita una procedura operativa che consente la valutazione della criticità dei difetti in rapporto al carico sostenuto, delineando anche la possibilità di un loro monitoraggio continuo mediante emissione acustica

APPLICAZIONI DELLA TOMOGRAFIA PULSE-ECHO ALL'INGEGNERIA CIVILE

Uno degli strumenti più innovativi attualmente disponibili per le indagini ultrasoniche su elementi in calcestruzzo è il tomografo A1040 MIRA, prodotto dalla Acoustic Control Systems di Mosca. Questo strumento è stato ideato per implementare sistematicamente la tecnica pulse-echo tramite una matrice di trasduttori a onde di taglio accoppiata ad un solo lato della struttura. Caratteristiche particolarmente interessanti di questo dispositivo sono i sensori puntiformi con accoppiamento a secco, l'implementazione automatica di sezioni tomografiche (scansioni B) tramite una specifica tecnica di focalizzazione e la possibilità di disporre dei dati grezzi acquisiti per l’implementazione di elaborazioni avanzate. Approfittando di quest'ultima opzione, gli autori hanno iniziato ad estendere l'uso di questo dispositivo ad alcuni problemi specifici al di là della semplice localizzazione dei vuoti. Un primo esempio è l'estrazione di informazioni quantitative sulla grandezza e sulla fase degli impulsi derivanti dai riflettori rilevati. Un'altra applicazione è la valutazione del danno superficiale dovuto all'esposizione al fuoco. L'ultimo esempio riguarda la ricerca dei difetti dominanti nei tiranti in ferro battuto con il metodo delle Onde Guidate. Qui i sensori adattabili a contatto puntiforme si sono rivelati molto efficaci nell'accoppiare lo strumento alla superficie irregolare degli elementi. Queste particolari applicazioni potrebbero rafforzare l'interesse per uno strumento diagnostico già affermato nel campo delle strutture civili

Metallurgical and mechanical characterization of the historical tie-rod of Duomo di Milano

Tie-rods have an important structural role in most of the vaulted constructions due to their capacity to balance the horizontal thrusts. However, their reliability in ancient buildings is often impaired by the manufacturing technology and the incidence of defects. One paradigmatic example is represented by Duomo di Milano, whose hand forged elements date back to the first half of the 15th century and have been the object of the metallurgical characterization herein presented. The occasion arose from the replacement of a deeply fractured tie-rod, two cross-sections of which were analyzed in details: one close to the breaking surface and the breaking surface itself. The investigations carried out on the first sample were aimed to characterize the material, while those performed on the second one were finalized to estimate the causes of the failure. Stereoscopy, light optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and Vickers hardness tests were employed to analyze the local chemical composition, microstructure and mechanical properties of the material. A good agreement among the results of these analyses was found. The insight into the quality of this wrought iron is of remarkable significance as concerns the representativeness of laboratory mechanical tests and the potential of diagnostic techniques for in-situ inspection