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Lateral Torsıonal Bucklıng Of Cantılever Ipe And Upe Steel Beams Wıth Nonlınear Fınıte Element Analysıs
No full textÇelik kirişler aynı anda eksenel kuvvet ve eğilme momenti etkisinde kalan yapısal
elemanlardır. Bu türdeki çelik kirişler için yanal çarpılarak burkulma göçme modu en fazla
risk yaratan ve istenmeyen göçme mekanizmalarının başında gelmektedir. Çelik kirişler
atalet momentlerinin yüksek olduğu yönde eğilme momenti etkisi altında eğilme
deformasyonu yaparken aynı anda düzlem dısında yatay deplasman ve burulma
deformasyonları da aynı yükleme etkisinde çok daha düşük bir kapasite düzetinde
oluşabilmektedir. İnce cıdarlı narin çelik kiriş elemanlarında yanal burulmalı burkulma
göçme mekanizması istenmeyen, aniden meydana gelen bir stabilite bozulması olup, bu
konuda yapılan deneysel ve nümerik çalışmalar son derece sınırlı sayıdadır. Yapılan
literatür taraması sonucunda çelik yapılarda yangın olarak kullanılan IPE ve UPE türü
profiller için yanal burulmalı burkulma stabilite bozulması için yapılan deneysel sonuçlar
ile karşılaştırılarak doğrulanmış kapsamlı bir nümerik çalışmanın olmadığı görülmüştür.
Bu nedenle nümerik bir çalışma planlanmış ve çalışma kapsamında 9 adet IPE160 ve 9
adet UPE80 konsol kiriş deney elemanının ABAQUS sonlu elemanlar programı
kullanılarak nümerik analizi gerçekleştirilmiştir. Nümerik sonuçlar deneysel sonuçlar ile
karşılaştırılmış ve ne ölçüde başarılı analiz sonuçları elde edilebildiği yorumlanmıştır.
Sonlu elemanlar analizi iki aşamada yapılmıştır. İlk aşamada her örnek için özdeğer
burkulma analizi yapılmıştır. Analiz sonucunda mod şekilleri elde edilmiştir ve elastik
kritik burkulma yükü hesaplanmıştır. İlk aşamadan elde edilen sonuçlarla bir geometrik
kusur belirlenerek ikinci aşamanın başlangıç modeli belirlenmiştir. İkinci aşamada,
geometrik ve malzeme nonlineerliği kullanılarak nonlineer risk analizi yapılmıştır. Bu
çalışma kapsamında önerilen sonlu elemanlar analizi prosedürünün, deneysel sounçlar ile
ne ölçüde uyumlu sonuçlar verebildiği incelenmiştir. Deneysel çalışma ve nümerik analiz
sonucunda elde edilen taşıma gücü, düşey deplasman ve burulma rotasyon açısı değerleri
karşılaştırılmış ve yorumlanmıştır. Nümerik analiz sonucunda elde edilen taşıma gücü
değerleri ve deneysel sonuçlar arasında çok daha büyük bir oranda benzeşim elde edilmiş
ve aralarında ortlama %0.66 fark olduğu hesaplanmıştır. Nümerik analiz sonucunda elde
edilen düşey deplasman ve burulma açısı değerleri, deneysel değerlerden sırasıyla ortalama
%11.03 ve %47.5 değerlerinde farklı elde edilmiştir.Steel beams are structural elements that are simultaneously under axial force and bending
moment. For this type of steel beams, the lateral torsional buckling failure mode is one of
the most risky and unwanted collapse mechanisms. While the steel beams bend under the
effect of bending moment in the direction of high moment of inertia, horizontal
displacement and torsional deformations at the same time can occur at a lower capacity
level under the same loading effect. In the thin-walled slender steel beam elements, the
lateral torsion buckling collapse mechanism is an undesirable, sudden deterioration of
stability, and experimental and numerical studies on this subject are extremely limited. As
a result of the literature review, it has been observed that there is no comprehensive
numerical study, which is validated by comparing the experimental results for lateral
torsional buckling stability deterioration for IPE and UPE type profiles which are widely
used in steel structures. For this reason, a numerical study was planned and a numerical
analysis of 9 IPE160 and 9 UPE80 cantilever beam test elements were made by using
ABAQUS finite element program. Numerical results were compared with experimental
results and the results of successful analysis were interpreted. Finite element analysis was
performed in two stages. In the first stage, eigenvalue buckling analysis was performed for
each sample. The mode shapes were obtained and the elastic critical buckling load was
calculated. A geometric imperfection was determined with the results obtained from the
first stage and the initial condition of the second stage was determined. In the second stage,
nonlinear riks analysis was performed by using geometric and material non-linearity. In
this study, the results of the proposed finite element analysis procedure compared with the
experimental results. As a result of experimental study and numerical analysis, the critical
buckling load, vertical displacement and maximum torsion rotation angle values were
computed and interpreted. A great similarity was obtained between the critical load values
obtained from the numerical analysis results and the experimental results and an average
difference of 0.66% was calculated. The vertical displacement and torsional angle values
obtained from the numerical analysis are different from the experimental values by 11.03%
and 47.5%
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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