1,720,962 research outputs found
A Material Model Optimization Approach for the Sheet Metal Forming Process Using the Hole Expansion Test
No full textPublisher Copyright: © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.Sheet metal forming is an important manufacturing process widely used to produce complex stamped parts from flat sheet stock in industries such as automotive and packaging. Due to the global economic climate, these industries need to be highly competitive by reducing production costs and increasing process efficiency. Numerical simulation combined with sheet metal forming expertise is one of the technological innovations adopted to meet these requirements by reducing the traditional time-consuming and costly testing steps. With the progress of finite element simulation, questions about the accuracy or limitations of the type of material description adopted have become particularly important. The influence of the plasticity model is examined in this work by a numerical study using the hole expansion test. This work first presents the yield locus criterion adopted and developed by Tata Steel, which is hereafter referred to as the Tata Steel material model. Hole expansion tests are performed at different hole diameters and the results are compared with FE simulation. The simulations are performed with the finite element software Autoform R11 in which the yield criterion proposed by Abspoel & Scholting [1] has been implemented. The discussion therefore focuses on the influence of the material model on the numerical predictions and its accuracy based on the optimization of the different material parameters measured.The authors would like to acknowledge experimental work carried out at Tata Steel R&D by Frank Schouten and Tushar Khandeparkar.Peer reviewe
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
Fracture toughness testing of Advanced High Strength Steels for automotive applications
No full textCarbon dioxide emissions from the transportation sector account for roughly one-third of world-wide CO2 emissions. Governmental pressure to tackle this problem has forced the industry to adapt with regard to material development. One such adaption is the development and application of advanced high-strength steels (AHSS), offering high specific strength combined with improved ductility. This enables lightweighting of consumer cars, as well as improving the overall occupant safety and crashworthiness. Despite these apparent advantages of AHSS, sheet metal forming operations can cause unexpected edge-cracking. In this research the occurrence of edge-cracking is investigated and rationalized with fracture toughness testing. The Essential Work of Fracture (EWF) methodology is applied on double-edge notched (DENT) specimens, an increasingly applied method to characterize the crack propagation resistance of thin sheet metal. A novel sample preparation method is evaluated here, based on sheared notches instead of fatigue pre-cracked specimens. The obtained fracture toughness parameters are validated against laboratory-scale deep-drawing experiments to estimate its predictive capabilities. Scanning electron microscopy (SEM) was employed to examine the fractured surfaces and to identify the relevant micro-mechanisms of fracture. It was found that the obtained EWF results are in good agreement with the observed cracking behaviour during deep-drawing. Both the established method (fatigue pre-cracking) as well as the novel method of sheared notches were able to reveal the intrinsically low fracture toughness, otherwise undetected with conventional tensile testing. From the fractured surfaces of the EWF samples the relevant micro-mechanisms of failure were identified that govern the fracture toughness properties. Transgranular cleavage fracture was responsible for brittle behaviour while failure ductile failure occurred via microvoid coalescence.Although the fatigue pre-cracking method for EWF testing seems to show a higher accuracy in predicting the cracking susceptibility, the shearing method can be employed as a rapid routine test to identify deterioration of fracture toughness properties early on
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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