1,721,300 research outputs found
Fatigue performance of metallic beams strengthened with a bonded CFRP plate
No full textThis paper gives details of a fatigue test programme of a series of small-scale steel beams bonded with a carbon fibre reinforced polymer (CFRP) plate. Backface-strain technique was used to detect crack initiation and monitor crack growth. Results show that this technique could detect crack initiation and track the deterioration of the adhesive layer. The strains recorded show that crack initiates and grows in Mode I earlier than in Mode II in the bonded joints, and this finding agrees with the observations on double-lap joints published in literature. The strains recorded also show that the adhesive spew fillet at the end of the CFRP plate is beneficial to the fatigue performance, although the improvement is not significant. An S–N curve was developed from the test results. The curve correlates the maximum principal interfacial stress at the plate end to the number of cycles to crack initiation. This maximum stress can be calculated from the authors’ previous analytical work. The fatigue limit of the S–N curve was found to be about 30% of the ultimate static failure stress
Design equation for offshore overlap tubular K-joints under in-plane bending
No full textOverlap tubular K-joints are generally regarded as having higher axial strength than similar simple gap K-joints due to their more direct load transfer between braces. Due to congestion at the nodes in steel jackets, overlap K-joints are used as key structural elements in many existing offshore platforms. However, relatively little experimental research has been done to quantify their strength and this has prevented engineers from taking full advantage of overlapping in the design of new structures as well as in the life extension assessment of existing platforms. This paper presents the results of a numerical study on gap and overlap K-joints under in-plane bending. The parametric study reveals new insight into how the behavior and strength varies across the practical range of geometrical parameters.
Based on the finite element strength database, a capacity equation has been derived and presented herein using nonlinear regression
analysis techniques
Strength prediction of ring-stiffened DT-joints in offshore jacket structures
No full textInternal stiffeners are commonly employed to enhance the strength of tubular joints found in off-shore steel jacket structures. However, there is a lack of detailed design guidance on the determination of their strengths in major offshore codes or design guides. This paper first summarises the results of a finite element study on tubular DT-joints with internal ring stiffeners subjected to axial brace compression. The study generated a database of twenty-two stiffened joints, some of which included multiple stiffeners. Observations on the development of plastic zones in the stiffeners show that the failure mechanism is the formation of plastic hinges from bending. A theoretical model based on the observed failure mechanism in the stiffener is then presented. The model is based on the upper bound theorem, with a postulated six-hinge collapse mechanism. The proposed theoretical model was found to provide strength predictions to a very high degree of accuracy
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
- …
