1,720,958 research outputs found
Study of an innovative joining solution for the wheel system
Get PDFThe objective of this thesis research is to develop an adhesive bonding solution in order to remove the classic welding technology exploited nowadays in the automotive steel wheel system.
The examined solution is an hybrid joint, based on adhesive boding combined with the presence of an interference fit. This hybrid joining technology consists in coupling two cylindrical components together by force-fitting one into the other after having placed an adhesive on the mating surfaces. This technique would allow the joining of dissimilar material to enable the design of hybrid lightweight wheels. Moreover, it would provide a better stress distribution in the joint area that could induce fatigue life improvement.
The contributions of the adhesive and the interference on the performance of the final hybrid joint is still not completely clear. In particular, the effect of the adhesive nature and of its mechanical and adhesive responses on the performance of the hybrid joint is under concern in this research. A study of the phenomena acting at the interference level is conducted at the laboratory level before industrial case application. An experimental method is set up in order to test the adhesives in a press fit joint. Static and dynamic tests are carried out examining the behavior of different adhesives, including rigid epoxies and flexible polyurethanes, and fractographic analysis are then performed.
The second part of the study is focused on the feasibility of the hybrid technology on the wheel system. Exploiting the outcomes of the laboratory analysis, bonded wheel prototypes are assembled and tested statically and dynamically, according to component validation in MW.
From the laboratory scale analyses it is found that the adhesive type mainly affects the static resistance of the hybrid joint. In particular the curing technology affects the decoupling behavior and the rheology influences the quantity of adhesive that remains inside the joint despites the interference levels. On the other hand, the interference rules the stiffness of the assembly and strongly affects the fatigue behavior of the cylindrical joint. The study conducted on the wheel component confirms the laboratory scale outcomes. For what concern the feasibility study, the bonded wheel shows similar performances compared to the welded wheel without design modifications of the components. However, the joint geometry has to be redesigned to exploit all the advantages of the adhesive bonding
THE HYBRID PRESS-FITTED ADHESIVE BONDED JOINT: THEORETICAL ASPECTS AND A PRACTICAL APPLICATION ON THE AUTOMOTIVE WHEEL
No full textNowadays, adhesive bonding is increasingly exploited in industrial applications, especially in multi-material lightweight structures, for its ability to join dissimilar materials together. In order to overcome the limits related to the durability of adhesives exposed to harsh environmental conditions, adhesive bonding can be used in combination with other joining techniques. This chapter examines the hybrid interference fitted-adhesive bonded joint and some design aspects for its practical application in a case study: the automotive steel wheel. An experimental evaluation of the contributions of the adhesive and the interference-fit to the resultant resistance of the hybrid joint was carried out with particular attention to the phenomena occuring at the interface level and the effect of the adhesive nature, its curing technology and its mechanical response. The outcomes of the laboratory analyses were validated in the steel wheel system. It was found that the adhesive contribution mainly affected the static resistance of the hybrid joint, and it was strongly related to the type of adhesive exploited. On the other hand, the interference-fit seemed to play an important role in governing the fatigue behaviour, especially in the wheel syste
Influence of the mechanical behaviour of different adhesives on an interference-fit cylindrical joint
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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
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