1,720,955 research outputs found
Experimental and analytical assessment of the racking behavior of timber frame walls with single-sided double-layered sheathing panels
No full textIn lightweight timber frame buildings, the horizontal stability against, for instance, wind loads is mainly ensured by shear diaphragms. These shear walls are typically constructed using a timber frame and a load- bearing sheathing layer on one or both sides of the framework. An atypical construction method uses double sheathing panels on top of each other, e.g. because of acoustic or fire safety reasons. However, no design rules are provided for such structures: the respective current and upcoming European standard (Eurocode 5 part 1-1) does not consider the structural contribution of both sheathing panel layers. Therefore, in this study, an experimental campaign is performed to enhance the knowledge of such double-sheathed shear walls, and two analytical calculation methods are proposed. The experimental campaign tests eight full-scale configurations through a racking resistance test with monotonic loading. Sheathing materials include load-bearing and non- load-bearing gypsum plasterboards and resinoid-bonded particle boards. All sheathing panels are connected to the fully anchored frames using staples. Results demonstrate that adding a second sheathing layer of the same material, with the same fastener disposition as the inner layer does not fully double the racking capacity and racking stiffness. Secondly, using a non-load-bearing gypsum plate as the inner layer creates a long plateau phase at the post-peak loading response, producing a less brittle failure behavior. The experiments are used as a benchmark to develop an analytical model based on Bla ss and Gebhardt's method for calculating the shear capacity of dowel-type connections with an interlayer. The proposed method introduces an interaction factor that takes into account that the connections of the outer sheathing layer, which pass through the inner sheathing layer, also contribute to the sheathing-to-framing connection of the latter. A simplified model is also presented, using a combination factor that aligns with the current Eurocode 5 design method for walls with sheathing panels on both sides of the framing. Different values for the respective interaction and combination factors are verified to determine a safe value for each tested configuration.The authors acknowledge the work of Jan Leuraers, Dan Dragan, and Frederick Truyers, who performed the experiments on the different wall configurations. Secondly, the authors gratefully thank VLAIO (Flanders Innovation & Entrepreneurship) for financing this research and Special Research Fund (BOF) of Hasselt University for supporting this research. VLAIO reference: HBC.2020.2098; BOF reference: BOF22OWB18
Experimental and analytical assessment of the combined in-plane bending-shear behavior of timber frame walls
No full textAs timber buildings grow taller, understanding the mechanical behavior and robustness of multi-story timber structures is increasingly important. In Europe, Eurocode 5 governs their design but offers little guidance for failure scenarios. In particular, it lacks provisions for diaphragm walls under combined bending and shear forces that can occur during events like wall loss. This study investigates the behavior of such walls through experimental and analytical methods. An experimental campaign was conducted using eleven timber frame walls with OSB sheathing, fastened with either screws or staples. Five walls underwent four-point bending tests, two were tested under shear, and four experienced combined bending-shear loading. In the latter, a vertical preload was applied before monotonic shear loading to failure. Walls fastened with staples showed ductile failure with significant yielding, whereas walls fastened with screws exhibited brittle failure via screw tear-out. Shear failures primarily occurred at sheathing-to-framing connections in the lower rail. Under combined loading, increased vertical preload reduced shear capacity, displacement at failure, and force at yielding. The experiments supported an analytical model developed to estimate in-plane bending strength and maximum allowable shear load in combined loading scenarios. The model conservatively predicted the behavior of walls fastened with screws in bending but overestimated the strength of walls fastened with staples. For combined loading, the model provided a conservative estimate of maximum shear resistance.The authors acknowledge the work of Jan Leuraers, Dan Dragan, and Ricky Pereira, who helped perform the experiments. Secondly, the authors gratefully thank the Special Research Fund (BOF) of Hasselt University, Belgium for supporting this research. BOF reference: BOF22OWB18
Experimental and analytical characterisation of hybrid timber-glass diaphragms with integrated photovoltaics
No full textThis study investigates the structural performance of hybrid timber-glass frame walls designed to enhance racking resistance in façades, with a specific focus on the integration of photovoltaic solar cells within structural glass elements. The effects of shear loads on the system’s components and the applicability of analytical design methods are evaluated. To achieve this, eight diaphragms (1.2 × 1.2 m) were tested under in-plane shear loading using two different structural silicone adhesives, with or without a tie-down anchoring of the leading stud. A variety of measurement techniques, including displacement sensors (LVDTs), digital image correlation, fibre Bragg gratings and strain gauges were simultaneously employed to analyse the behaviour of the different components. The specimens primarily failed due to adhesive rupture. It is shown that adding wall anchorage increases the system’s racking stiffness by 30%. This study offers insights into the strains measured on the glass and solar cells during mechanical in-plane shear load tests. Furthermore, an analytical design method based on the relevant Eurocode (prEN 1995-1-1) and spring models is proposed and compared with the experimental results. The findings reveal that while this method tends to underestimate the stiffness of the wall elements, it provides an accurate prediction of the minimum load-bearing capacity.The authors acknowledge the work of Dan Dragan and Niels Blocken who performed the experiments on the different diaphragm configurations. Secondly, the authors gratefully thank the Special Research Fund (BOF) of Hasselt University for supporting this research with project Number BOF21DOC17. Special thanks go to Dow Silicones Belgium SPRL, particularly Valerie Hayez and the involved laboratory members, for their assistance in specimen production and technical support. Appreciation is also extended to Kömmerling Chemische Fabrik GMBH, notably Christian Scherer and his colleagues, for their engaging discussions and assistance with specimen production. The authors are also thankful to Soltech NV and Tatjana Vavilkin for their contributions to solar panel production, along with DUPAC NV for providing the necessary timber. Additionally, they recognise the experimental efforts of Jasper van Berlo and Ruben Wagemans related to their master’s thesis
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
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