1,720,984 research outputs found
Deformation capacity of reinforced concrete beams: new insights for the assessment of sound and corroded members
Full text linkLe strutture e le infrastrutture civili possono essere esposte a vari rischi che possono indurre sollecitazioni aggiuntive oltre a quelle dovute ai carichi di servizio. In varie situazioni, le strutture devono essere in grado di deformarsi senza ridurre significativamente la loro resistenza e senza raggiungere il collasso, almeno in una certa misura. In altre parole, devono avere una sufficiente capacità deformativa. Tale proprietà è ad esempio molto utile per accomodare la ridistribuzione delle azioni interne nelle strutture iperstatiche, nonché per evitare collassi dovuti a deformazioni imposte, come quelle dovute ai cedimenti differenziali del terreno sottostante le fondazioni. Inoltre, in molti casi la capacità deformativa in campo anelastico risulta veramente una proprietà fondamentale, ad esempio affinché le strutture possano sopravvivere a forti terremoti senza crollare.
In questo lavoro si affronta il tema della capacità deformativa di travi in calcestruzzo armato, fornendo innanzitutto un approccio analitico per analizzare la capacità deformativa e la duttilità a livello sezionale. Successivamente, vengono analizzate le capacità predittive di diversi approcci di modellazione analitica e numerica, con l'obiettivo di verificare la loro capacità di fornire stime delle modalità di rottura e della capacità deformativa di travi in calcestruzzo armato sia sane che corrose, evidenziando alcuni degli attuali limiti di questo tipo di approcci. Infine, al fine di favorire possibili miglioramenti nella stima delle domande di deformazione in edifici soggetti a cedimenti differenziali del terreno, è stata analizzata l’applicazione di una promettente tecnica di telerilevamento satellitare (MT-DInSAR) per il monitoraggio delle deformazioni del terreno in aree urbane, evidenziandone le principali potenzialità e gli attuali limiti.
Complessivamente, gli strumenti e gli spunti proposti nel presente lavoro auspicano ad essere utili per favorire il miglioramento delle pratiche ingegneristiche impiegate per la progettazione e la verifica strutturale delle costruzioni in calcestruzzo armato.Civil structures and infrastructure can be exposed to various hazards that can induce other internal actions in addition to those due to service loads. In various situations, structures need to be able to deform almost not reducing their strength and without fail, to some extent. In other words, they must have sufficient deformation capacity.
Such an ability is for example very useful to accommodate redistribution of internal actions in statically indeterminate structures, as well as to avoid failure due to imposed deformations such as those due to differential ground settlements below the foundations. In addition, in many cases inelastic deformation capacity really is a fundamental property for structures, e.g. when they should be able to survive strong earthquakes without collapsing.
In this work, deformation capacity of reinforced concrete beams is addressed, first providing an analytical framework to analyze deformation capacity and ductility at sectional level. Then, the simulation performances of different practice-oriented analytical and numerical modelling approaches are tested, with the aim of check their capability in providing estimations of the failure mode and deformation capacity of both sound and corroded reinforced concrete beams, understanding some of the current limits of this type of approaches. Finally, in order to foster possible improvements in the estimation of deformation demands in buildings subjected to ground settlements, the applications of a promising satellite remote sensing technique (MT-DInSAR) to monitor ground deformations in urban areas has been analyzed, highlighting major potentials and current limitations.
Overall, the tools and insights proposed in the present work aim to be useful in fostering the improvement of engineering practices employed for performance-based design and assessment of reinforced concrete structures
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Non-destructive techniques for structural characterization of cultural heritage: A pilot case study
Full text linkThis work describes an approach for combining local and global non-destructive techniques for the structural characterization and conservation assessment of cultural heritage buildings. An experimental investigation program was conducted on the south vault of St. Mark's Basilica in Venice, involving historical investigations, a damage survey, sonic tests, and ambient vibration measurements. Recorded data were employed to assess the material and structural properties of the vault and to characterize the observed damage pattern. The study of the correlation between results of sonic tests and ambient vibration measurements has shown how, in complex structural typologies, the information provided by both these two kinds of tests are necessary in order to effectively characterize the structural behaviour, which is strongly influenced by the complexity of geometry and restraint condition. Experimental results have been used for the validation of a numerical model adopting a non-conventional approach. The procedure is based on comparing numerical simulation of ambient vibration response in terms of the frequency content of acceleration signals. This approach can be performed using only a limited number of measured acceleration signals, proving to be useful and cost-effective. The work aims to provide helpful insights into the combined use of non-destructive tests for the efficient structural characterization and safety assessment of heritage structures
Influence of geometry and material parameters variability on the ultimate condition of doubly reinforced concrete beams
No full textAnalytical formulations for the study of ultimate curvature capacity of reinforced concrete members are useful in design practice, especially for preliminary definitions of member characteristics in order to achieve a ductile behavior. This work, part of a broader research, analyzes the influence of various parameters on failure mode of doubly reinforced concrete beams. Differently from classical approaches, in this work all possible ultimate configurations are considered. An approach for identification of ulti-mate condition based on failure mode domains are developed analitically. It is shown that variations of reinforcing steel amount and ultimate deformation capacity can strongly affect the failure mode of the section and, consequently, its deformation capacity and ductility
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