1,720,958 research outputs found
Capacity assessment of existing RC columns taking into account bi-axial shear failure
No full textSeveral scenarios can trigger bi-axial shear in reinforced concrete (RC) vertical members such as wind actions, earthquake, fire, and explosions. In this paper, bi-axial shear scenarios are analysed and the capacity of corroded RC members such as columns or bridge piers is evaluated. Firstly, the interaction between bending moment and shear force, combined with cyclic degradation is analytically evaluated. To this aim, the recent formulation proposed by Biskinis and Fardis for the assessment of the uni-axial shear resistance is extended to plot the bi-axial failure criterion, while the ductility is evaluated by considering the effect of the bi-axial bending moments and the applied axial force. Finally, design provisions are given in order to propose adjustments to the formulations provided by standard Codes and Guidelines that allow to take into account the effect of corrosion in the assessment of the bia-axial shear resistance of RC members
LONG-TERM AND CORROSION EFFECTS ON THE PUNCHING SHEAR RESISTANCE OF RC FLAT SLABS SUBJECTED TO SUDDEN COLUMN LOSS
No full textDuring an extreme event occurring on a reinforced concrete structure, characterized by the loss of a load-bearing element, the remaining resisting members may develop alternate load paths to resist gravity loads. However, it is recognized that reinforced concrete flat slabs are prone to punching shear failure. This issue is particularly relevant for existing reinforced concrete structures where creep, shrinkage, and corrosion effects due to environmental conditions play a fundamental role before the occurrence of the extreme event. In this paper, nonlinear pushdown and dynamic analyses were performed on an existing continuous reinforced concrete flat slab to investigate the structural response in the case of an interior column loss. Firstly, the flexural and membrane action resisting contributions were in-deeply analyzed. Secondly, the crucial effects of creep, shrinkage and corrosion on the dynamic response and punching shear resistance of the system were critically evaluated. Finally, useful insights for the structural robustness assessment of existing RC structures subjected to material deterioration were provided
Numerical assessment of the load-bearing capacity and reliability of existing bridges with dapped-end beams
No full textThe aim of this work is to evaluate the structural reliability of a corroded dapped-end beam belonging to an existing 70-year-old reinforced concrete bridge, by comparing the results obtained from a semi-probabilistic method with those provided by a fully probabilistic approach using Monte Carlo simula-tions. The resistance of the element was evaluated through a strut-and-tie model where corrosion was applied, considering both the initiation and propagation periods. The study highlights the potential of semi-probabilistic analyses while recognising the superior accuracy of full-probabilistic methods
Numerical approach to evaluate the load bearing capacity of RC dapped-end beams subjected to corrosion
No full textIn this paper, the load-bearing capacity of a RC dapped-end beams subjected to corrosion is analyzed
by proposing a numerical approach. In particular, nonlinear finite element analyses (NLFEA) are carried
out by adopting a multi-layered shell element approach with the PARC_CL 2.1 crack model implemented
as user subroutine in Abaqus. Firstly, to validate the numerical approach, the FE results are
compared against uncorroded dapped-end beams. Secondly, the degradation effects induced by corrosion
are investigated by considering: (i) the cross-sectional and mechanical properties reduction of reinforcing
steel bars and (ii) the steel-to-concrete interaction. Finally, the relevant results are outlined
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
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