1,720,956 research outputs found
DELAMINATION BUCKLING AND GROWTH OF COMPOSITE LAMINATED PLATES WITH TRANSVERSE-SHEAR DEFORMATION
No full textAn analytical method was presented to determine the delamination buckling load and the growth of one-dimensional delaminated beam-plates. In this study, the symmetry in delamination with respect to the center of the beam-plate was not assumed. The delamination was arbitrarily located in the longitudinal and thickness directions. The effects of the delamination length, and location on the buckling load and the growth were investigated with consideration of the transverse shear deformation. Results of the analysis showed that the delamination buckling load was dependent on the configuration of the delamination. For the relatively thick delamination, the buckling load of a center located delamination was higher than that of an off-center delamination. The shear deformation effect lowered the buckling loads and increased the energy-release rates. The expreiments on delaminated graphite/epoxy unidirectional specimens were also performed to determine the buckling load and to observe the growth characteristics. Results of the experiments showed good agreement with analytic results and there existed various postbuckling characteristics depending on the configuration of delamination
Delamination Buckling and Growth of Composite Laminated Plates with Transverse Shear Deformation
No full textModeling of composite laminates with multiple delaminations under compressive loading
No full textMultiple delaminations are more realistic damage types in the laminated composite structures. In this study, buckling and postbuckling analysis was conducted for the composite laminates with multiple delaminations under compressive loading. In a nonlinear finite element formulation, the updated Lagrangian description and modified arc-length method were adopted. For a finite element modeling of composite laminates, the eight-node degenerated shell element was used. To avoid the overlapping between delaminated layers, which is a physically inadmissible buckling mode, the contact node pair was defined by use of virtual beam element. It employed constraints at the overlapped region in the load incremental procedure. Using this modeling of multiple delaminations, accurate results were obtained for the buckling and postbuckling behavior of composite laminates. Numerical results showed that multiple delaminations lower buckling loads and load carrying capacities in the postbuckling region
Buckling and postbuckling behavior of composite cross-ply laminates with multiple delaminations
No full textIn this study, buckling and postbuckling analysis was conducted for the composite cross-ply laminates with multiple delaminations under compressive loading. The geometries of multiple delaminations are a one-dimensional through-the-width type and a two-dimensional embedded circular type. In a nonlinear finite element formulation, the updated Lagrangian description and the modified are-length method were adopted. For a finite element modeling of composite laminates, the eight-node degenerated shell element was used. To avoid overlapping between delaminated areas, the contact node pair was defined by virtual beam element. Numerical results showed that multiple delaminations lower buckling loads and load carrying capacities in the postbuckling region. The buckling load varies with the projected area of the delaminations, However, the geometry of multiple delaminations has an influence on the postbuckling behavior. The load carrying capacity differed with the distribution type due to the local reduction of bending stiffness and the contact behavior of the sublaminates
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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