1,720,967 research outputs found
Modelling the bond in GFRP bar reinforced concrete thin structural members
Full text linkThis paper analyses the accuracy of FE (Finite Element) modelling of concrete thin slabs, reinforced with GFRP (Glass Fiber Reinforced Polymer) bars, under bending loading conditions. It considers two strategies of concrete/bar interaction approach – direct and indirect. Indirect bond approach was combined with concrete tension stiffening model, whereas the direct bond one employed plain concrete constitutive model. Apart from selection of material and bond models, FE mesh sensitivity was examined. The efficiency of both bond modelling strategies was proven for the slab of standard thickness (100 mm) failed due to concrete crushing, whereas direct bond method was shown indispensable when simulating very thin slabs (40 mm) failed due to bar debonding
Numerical modelling of GFRP reinforced thin concrete slabs
No full textWith the development of new glass fiber reinforced polymer (GFRP) bars for RC structures, their application extends simultaneously. The non-corrosive nature of GFRP bars enables maximal lowering of the concrete cover, thus making them very suitable as a reinforcement in thin RC plate elements. Such thin members are usually prefabricated and used as façade panels, pavement or components of sandwich panels. Along with experimental studies, the finite element (FE) numerical modeling represents very useful tool for assessing and predicting the structural member behavior. Proper choice of material constitutive models and strategy of concrete/bar bond implementation always presents challenge when dealing with numerical FE modelling of RC structures. This study considers FE modelling of thin GFRP RC slabs’ flexural behavior under three-point bending test setup. It uses direct bond approach, that is, explicit simulation of the bond-slip effect between concrete and reinforcing bars. For this purpose, the experimental bond-slip law was used, obtained from the pull-out test having the same GFRP bar, same concrete cover and similar concrete properties as simulated RC slab. Since the slab failed for concrete crushing, the study assesses the importance of concrete compressive model selection on the numerical analysis results. Two different models were employed in the numerical analysis, in combination with three FE mesh densities. The main differences between the models comprise post-peak capacity and mesh dependency. The FE modelling strategy developed in the study was shown successful in reproducing the experimental outcome. Both concrete models showed convergence tendency when refining the mesh, whereas only one of them succeeded to reproduce the experimental results
Effect of Small Concrete Cover on the Fatigue Behavior of GFRP Bars and Concrete Bond
No full textThe paper deals with the influence of cyclic loading on the bond between glass-fiber-reinforced polymer (GFRP) bars and concrete. The experimental study considers eccentric and centric pullout tests that vary by three different parameters: (1) concrete cover; (2) concrete strength; and (3) maximum load applied during cyclic loading. The results showed that the fatigue life of the bond between the considered GFRP rebars and concrete, with a small cover and low concrete quality, is limited by the occurrence of splitting failure. As the cover increases, the fatigue failure mode becomes a combination of splitting and bar pullout. The mechanical properties of concrete have a positive effect on fatigue life. (C) 2018 American Society of Civil Engineers
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
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