1,720,961 research outputs found
Numerical simulation of substandard beam-column joints with different failure mechanisms
No full textGenerating the nonlinear behavior of substandard beam-column joints is challenging. Difficulties arise even more in reproducing the contribution of different nonlinear mechanisms (and their mutual effects) on the global cyclic response. This paper deals with the advanced numerical modeling of substandard reinforced concrete (RC) beam-column joints designed with structural details and material properties non-conforming to current seismic codes. Refined numerical models developed in VecTor2 and ATENA Science finite element (FE) software are investigated in detail to identify the factors affecting the global and local joint response. Two different modeling strategies are closely compared with experimental results of joint subassemblies with different failure modes in terms of hysteric response, crack pattern and its development, and local deformations at the joint panel and framing members. The advantages-disadvantages, difficulties in implementing the numerical model and their capability to reproduce the experimental behavior are discussed in detail. The comparison against experimental results in terms of local and global response is useful to assess the accuracy of the proposed models and it provides details on their applicability
Effectiveness of seismic retrofitting of a historical masonry structure: Kütahya Kurşunlu Mosque, Turkey
No full textCrack width-based fragility curves for repairability of substandard beam-column joints
No full textPost-earthquake observations have outlined the poor seismic performance of substandard reinforced concrete (RC) beam-column joints in existing buildings. They often exhibit significant cracking even under moderate intensity earthquakes, compromising the seismic performance of the entire building. This makes the quantification of their residual capacity and the definition of reliable repairability thresholds critical. Different approaches are available in the literature to establish the repairability of RC joints. However, a simple crack width-based criterion is required for practitioners during in-situ inspections. This study deals with the definition of crack width-based fragility curves relying on numerical analyses. Those are carried out by using the validated finite element (FE) models, being capable of reproducing the initiation and development of cracks in RC joints. To this end, the uncertainties in material properties, influencing the seismic performance of structural components, are accounted for different joints. In particular, experimentally validated FE models are evolved to stochastic level by generating random variables of material properties with the stratified sampling scheme. Fragility curves representing a certain level of probability of exceeding the defined crack width at the joint back, joint core, and beam-to-joint interface are developed. An application of the proposed methodology for in-situ inspections is also presented, and the results of in-situ measurements of residual crack width from real buildings damaged by recent earthquakes are used for the validation
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
Finite element modeling and operational modal analysis of a historical masonry mosque
Get PDFFinite Element Modeling (FEM) and Operational Modal Analysis (OMA) is herein presented for the historical masonry Kütahya Kurşunlu Mosque within the framework of its seismic performance assessment. The historical structure is located in Turkey which has a high-level seismic activity. A FEM strategy was adopted to construct a numerical model of the structure considering a simplified three-dimensional geometry and a macro-modeling approach for the masonry. A representative numerical model of the existing structure was calibrated and improved according to the OMA results obtained from ambient vibration measurements, performed in-situ. The ambient vibration measurements were operated by using two triaxial accelerometers, that one of the accelerometers was regulated as a reference station whereas the other accelerometer was relocated to seven different points on the top of the walls. Identification of the experimental modal parameters was achieved by performing two different signal processing methodologies, namely the Enhanced Frequency Domain Decomposition (EFDD) and the Stochastic Subspace Identification - Unweighted Principal Components (SSI-UPC). Results obtained from both methods were compared in terms of the Modal Assurance Criterion (MAC) which considers the mode shapes derived in a specific range of frequency. The SSI-UPC method was employed in achieving the experimental modal response of the structure and the results were compared with the eigenvalue analysis results of the preliminary numerical model. A calibration process was carried out in terms of minimizing the difference between the experimental and numerical modal response by a trial and error approach and an average error of 4.9% was calculated for the modal frequencies of the first four global modes of vibration
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
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