1,721,032 research outputs found
Fatigue assessment of high strength welded joints through the strain energy density method
Full text linkThe main aim of the present work is to investigate, through the strain energy density method, the fatigue behaviour of high strength welded joints realised employed in hydraulic runner blades. The geometries, found in literature, present the welding bead machined in order to have no geometrical discontinuities in the specimen realising a wide fitting radius between the two welded plates; the only critical geometrical discontinuity in the specimen is given by the lack of penetration that leads to an internal crack-like defect. The specimens presented failure both from the weld toe and from the weld root depending on the amount of welding penetration. The results, summarised in this work with the strain energy density method, show clearly the possibility to consider a unique master curve for this kind of joints regardless of the failure initiation point. Acquiring, through a finite element model, the strain energy density value both at the weld toe and at the weld root and comparing them, the method is proved to be adequate to detect the most critical area of the joint. A first fatigue master curve in terms of cyclic averaged strain energy density value is provided for the fatigue design of high strength welded joints. © 2020 The Authors. Fatigue & Fracture of Engineering Materials & Structures published by John Wiley & Sons Lt
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
Multiaxial fatigue of additively manufactured metallic components: a review of the failure mechanisms and fatigue life prediction methodologies
No full textAdditive manufacturing techniques offer significant advantages over conventional manufacturing methods. These include the possibility of realizing highly customized components in which not only can the geometry be defined with a high degree of freedom, but the material composition or geometrical properties can also be manipulated throughout the component by introducing lattice structure zones. Such variations cannot be realized using conventional manufacturing techniques. However, the application of additively manufactured parts at the industrial scale is still limited owing to the high variability in mechanical properties, which also makes it difficult to define feasible tools to assess their structural integrity and determine their expected fatigue life with a sufficient degree of reliability. In addition, real components often experience multiaxial stresses at critical locations owing to their geometry or service-loading conditions. Thus, a proper under-standing of the fatigue performance of additively manufactured components with complex ge-ometries cannot neglect the consideration of multiaxial stress states. This review presents an overview of multiaxial fatigue in additively manufactured metallic components, providing in-sights into crack initiation sites and growth orientations and relating them to the fatigue failure mechanisms in these components. The principal life prediction methodologies applied for the fatigue damage assessment of additively manufactured components under multiaxial fatigue loading are presented, with a particular focus on their accuracy in correlating fatigue data ob-tained for different loading conditions
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