1,720,968 research outputs found
Assessment of seismic behaviour of heritage masonry buildings using numerical modelling
No full textThe paper analyzes the seismic vulnerability of the historical complex of “San Francesco” located in Cagli, Marche Region, Italy. It provides both advanced 3D modelling with solid elements and equivalent frame modelling. The building is composed of a church and a monastery used as a lower secondary school, and preservation and maintenance of its structural efficiency are of primary importance. The global structural behaviour and dynamic properties of the compound have been evaluated using the Finite Element Modelling (FEM) technique, where the nonlinear behaviour of masonry has been taken into account by proper constitutive assumptions. A sensitivity analysis is done to evaluate the effect of the choice of the control point on the value of seismic risk index, by varying the stiffness of the floors and the effects of different knowledge levels. The aim of the paper is to emphasize the importance of thorough knowledge of historic buildings in order to understand the real seismic behaviour of a structure, to detect common vulnerability of this type of building, the knowledge of which is necessary to design restorations aimed at improving the seismic behaviour of masonry buildings. Some comparisons with the Equivalent Frame Method (EFM) are also presented
Influence of FE Modelling Approaches on Vulnerabilities of RC School Buildings and Proposal of a CFRP Retrofitting Intervention
No full textBackground: The vulnerability assessment of existing school buildings against earthquakes represents a priority concern for society. In recent years, several countries promote seismic rehabilitation projects of school buildings, including the allocation of funds to regions with high seismic hazard. Objectives: This research aims to highlight some key role aspects related to difficulties encountered in the numerical modelling of RC structures hosting school activities. This work evaluates the seismic vulnerability of school buildings located in the municipality of Trecastelli (Marche, Central Italy) to quantify the effective influence of typical and specific seismic vulnerabilities detected on the global seismic behaviour of each building. The effectiveness of a possible Carbon Fibre Reinforced Polymer (CFRP) local strengthening intervention, for the case study, aimed to confine unconfined beam-column joints is also considered. Methods: Three different numerical models of a Reinforced Concrete (RC) school building are implemented with the lumped plasticity, the distributed plasticity (fibre) and the 3D Continuum Finite Element (FE) approaches. Nonlinear static (pushover) analyses are performed to assess the global seismic behaviour of the structure, and the limitations to represent the reality with different approaches. After the seismic vulnerability assessment of the case study, a CFRP retrofitting intervention is proposed to confine external beam-column joints. Results: The comparison of the numerical results of three models shows that the fibre model is the least suitable means to represent shear problems, while the lumped plasticity model is closer to reality than the previous one even if it does not take into account the concomitance of bending, shear and axial force and the interaction between them in the inelastic response. Of course, the 3D Continuum model is the most accurate representation to describe the complex and combined mechanisms developed in the joint panels. Nonlinear static (pushover) analyses carried out on unreinforced and reinforced structures of Continuum model demonstrate that the Fibre Reinforced Polymer (FRP) strengthening improves the displacement capacity of the structure. Conclusion: This study has highlighted the strengths and weaknesses of different modelling types. The meaningful information about mechanisms developed in joints given by the 3D Continuum FE model is useful to identify shortcomings of the design project and to conceive a retrofitting strengthening intervention. CFRP sheets externally bonded on beam-column joints may improve the seismic frame performances without a significant change of the structural stiffness, promoting a ductile failure mode with a higher displacement capacity than the unreinforced case
Modal parameters identification with environmental tests and advanced numerical analyses for masonry bell towers: A meaningful case study
No full textIn the first part, a dynamic monitoring for non-destructive evaluation of heritage structures is discussed with reference to a case study, namely the Pomposa Abbey belfry, located in the Ferrara Province (Italy). The main dynamic parameters constitute an important reference to define an advanced numerical model, discussed in the second part, based on Non-Smooth Contact Dynamics (NSCD) method. Schematised as a system of rigid blocks undergoing frictional sliding and plastic impacts, the tower has exhibited complex dynamics, because of both geometrical nonlinearity and the non-smooth nature of the contact laws. First, harmonic oscillations have been applied to the basement of the tower and a systematic parametric study has been conducted, aimed at correlating the system vulnerability to the values of amplitude and frequency of the assigned excitation corroborated by the dynamic identification results. In addition, numerical analyses have been done to highlight the effects of the friction coefficient and of the blocks geometries on the dynamics, in particular on the collapse modes. Finally, a study of the tower stability against seismic excitations has been addressed and 3D simulations have been performed with a real earthquake
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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