1,720,956 research outputs found
Seismic analysis and design of innovative steel and concrete hybrid coupled wall systems
No full textL’applicazione del concetto di fusibile strutturale nei sistemi sismo-resistenti ha portato allo sviluppo di diverse soluzioni strutturali, tra queste sono compresi i promettenti sistemi ibridi acciaio calcestruzzo. Questi sistemi sono ottenuti tramite una combinazione in serie di elementi in acciaio e in calcestruzzo armato con l’obiettivo di sfruttare al loro meglio le potenzialità di ciascun materiale. In questo lavoro viene indagato il comportamento sismico del sistema innovativo ibrido a parete accoppiata (HCSW), sviluppato nel progetto di ricerca europeo INNO-HYCO (INNOvative HYbrid and COmposite steel-concrete structural solutions for building in seismic area). La soluzione sismo-resistente è composta da una parete in calcestruzzo armato accoppiata a colonne laterali di acciaio tramite link sostituibili con l’obiettivo di sfruttare sia la rigidezza della parete, necessaria a limitare il danneggiamento della costruzione sotto l’azione di terremoti di bassa intensità, che la duttilità dei link di acciaio, necessaria a dissipare l’energia dei sismi di medio-alta intensità. Il comportamento sismico del sistema viene valutato tramite analisi statiche non lineari (pushover) e analisi dinamiche non lineari incrementali (IDA). Per questi scopi, inizialmente è stato progettato un insieme di casi studio realistici, poi è stato sviluppato un modello agli elementi finiti a fibre, validato successivamente tramite confronti con risultati sperimentali comprendendo quantità di risposta locali e globali. Infine, viene mostrata una selezione dei risultati ottenuti, includendo parametri di risposta locale e globale, per mettere in luce le potenzialità dei sistemi innovativi proposti e la concreta possibilità di sviluppare un comportamento duttile nel quale le deformazioni plastiche nei link sono attese prima dello snervamento della parete. Inoltre, i risultati finali permettono di fornire un supporto per l’identificazione delle soluzioni ottimali che potrebbero risultare competitive rispetto a sistemi esistenti
Nonlinear seismic response analysis of an innovative steel and concrete hybrid coupled wall system
No full textThe seismic response of an innovative hybrid coupled shear wall (HCW) system, obtained through the connection of a reinforced concrete (RC) wall to two steel side columns by means of steel links, is studied. This structural solution is conceived to exploit both the stiffness of the RC wall, required to limit building damage under low-intensity earthquakes, and the ductility of the steel links, necessary to dissipate energy under medium- and high-intensity earthquakes. The seismic performance of the proposed HCW system is evaluated through multi-record nonlinear dynamic analysis of a set of case studies designed on the basis of a specific ductile design procedure. The adopted finite element models are illustrated and validated against experimental tests and more complex three-dimensional numerical models. A selection of results is presented and discussed to highlight the potentialities of the proposed innovative HCW systems and the possibility to develop a ductile mechanism where plastic deformations are mainly attained in the steel links with minor damages in the RC wall
Analisi sismica di edifici prefabbricati con connessioni deformabili
No full textNel contesto nazionale le strutture prefabbricate monopiano risultano in larga parte
concepite mediante concezioni strutturali superate dagli attuali criteri antisismici. Gli eventi sismici
recenti e del passato hanno evidenziato come la loro vulnerabilità sia spesso associata alle connessioni tra
elementi strutturali. Le norme attuali risultano tuttavia carenti nel fornire indicazioni in merito alla
progettazione e alla modellazione delle stesse. Nella presente memoria viene presentata una procedura di
modellazione delle connessioni a spinotto per la valutazione della vulnerabilità sismica degli edifici
esistenti. La metodologia proposta viene applicata a due capannoni industriali esistenti. Dai risultati delle
analisi dinamiche lineari e statiche non lineari condotte è emerso che una modellazione delle connessioni
rigide può portare a sovrastime della domanda sismica in esse e alla variazione della risposta sismica
globale dell’edificio, modificando l’esito delle verifiche di sicurezza sia globali che locali
Influence of connections modeling on the seismic behaviour of industrial buildings
No full textMany industrial buildings with a precast concrete structure have been designed in accordance with non-seismic provisions by considering only gravity loads or, in some other cases, in accordance with not adequate seismic detailing requirements .In particular, seismic events that occurred in the recent past have shown that the connections between the main structural elements play an important role on the dynamic and seismic behaviour of the pre-cast concrete structure. Nowadays, the more advanced technical standards require mechani-cal connections between the precast elements; however codes do not furnish exhaustive information about the design and modelling of these connections neither in the seismic vul-nerability assessment of existing buildings nor in the design of new constructions
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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