Documents published in 2019 : Scipedia

Journalists view on the evolution of the (metaphorical) ecosystem of communication about health and biomedicine
G. Revuelta-de-la-Poza

El profesional de la información (2019). Vol. 28, (2), 82

Abstract
The perception of specialized journalists about the transformations of public communication of health and biomedicine in Spain in the last two decades was analysed. Twenty semi-structured interviews were performed. In the analysis, the metaphorical concept of "ecosystem" has been used. According to the interviewees, the main "environmental" changes have been technological (highlighting the expansion and diversity of online information and the impact of social networks). There is a multiplication and diversification of the "species" of information sources. Within this, specialized sources (researchers and health professionals) and civil associations (patients and consumers) have increased their visibility, but "opportunistic species" have also emerged, such as the promoters of fake-news and pseudotherapies. Despite recognizing that their work "environment" has worsened and perceiving the dependence on clickbait and network positioning as a threat, health journalists value their profession with satisfaction.
Abstract
The perception of specialized journalists about the transformations of public communication of health and biomedicine in Spain in the last two decades was analysed. Twenty [...]
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Dr. Google, what can you tell me about homeopathy? Comparative study of the top10 websites in the United States, United Kingdom, France, Mexico and Spain
L. Cano-Orón

El profesional de la información (2019). Vol. 28, (2), 80

Abstract
Users access to Google to find out about health issues is frequent among citizens. This research analyzes the best results of three generic searches on homeopathy, collected in four waves in five countries: Spain, France, Mexico, the United Kingdom, and the United States. Specifically, the fluctuation of the corpus ranking is studied, and a sample of the ten best-positioned pages in each country is taken to analyze their content (the authorship of the website, the stance of the effectiveness of homeopathy, the presence of controversy and the type of content). The results show that the ranking is stable; that the stance of homeopathy is linked to the state of public opinion in the country; the majority of better-positioned websites being of news published in the media.
Abstract
Users access to Google to find out about health issues is frequent among citizens. This research analyzes the best results of three generic searches on homeopathy, collected [...]
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Editorial: La relevancia del evaluador de una publicación científica
L. Casadei

Gaceta Técnica (2019). Vol. 19, 7
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Analysis of vaccine and anti-vaccine information on social networks and internet. Visual and emotional patterns of their stimulus
U. Cuesta-Cambra, L. Martínez-Martínez, J. Niño-González

El profesional de la información (2019). Vol. 28, (2), 78

Abstract
This research analyzes the flow of information and communication about vaccines and anti-vaccines through the monitoring of issuers, groups, news sites and messages in RRSS. We also investigate its effects on attention, emotion and engagement analyzed with Eye Tracking, GSR and Facial Expression respectively. Results: the flow of communication is unstable, in press and sites and informative and neutral tendency, often with non-professional sources. On RRSS, anti-vaccine Facebook messages and groups are identified and an exploratory mapping of influencers is presented. Analysis of the temporal evolution (years 2015 to 2018) of communicative flows showed a positive evolutions: antivaccine tendencies decrease. Emotional responses and engagement do not show differences between antivaccines and vaccines: this important data is interpreted in the terms of processing by heuristics. Gender differences appeared in the pattern of exploration of the information and the emotion provoked (GSR and Expression).
Abstract
This research analyzes the flow of information and communication about vaccines and anti-vaccines through the monitoring of issuers, groups, news sites and messages in RRSS. [...]
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Disruption index depends on length of citation window
L. Bornmann, A. Tekles

El profesional de la información (2019). Vol. 28, (2), 76

Abstract
In the context of recent developments in scientometrics to measure novelty or creative potential, Wu, Wang, and Evans (2019) propose a new disruption index that measures the extent to which a publication disrupts the field of science. We calculated the disruption index for some example papers. The analyses of the index values (using our Web of Science in-house database) show that they depend on the citation window (the period of time over which citations are collected).
Abstract
In the context of recent developments in scientometrics to measure novelty or creative potential, Wu, Wang, and Evans (2019) propose a new disruption index that measures the [...]
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Active audiences and social discussion on the digital public sphere. Review article
P. Masip, C. Ruiz-Caballero, J. Suau

El profesional de la información (2019). Vol. 28, (2), 74

Abstract
In little over a decade, essential concepts in research on communication have become zombie concepts (Beck; Willms, 2004) and are no longer effective for understanding the profound transformation that has taken place with the arrival of the internet. Public sphere, deliberation, audiences, public... the academic literature has oscillated between an initial optimism about the potential for strengthening democracy of communication technologies to a critical scepticism. This text reviews the academic literature with regard to the forms of social deliberation adopted in the context of the media and social networks and its impact on the public sphere.
Abstract
In little over a decade, essential concepts in research on communication have become zombie concepts (Beck; Willms, 2004) and are no longer effective for understanding the [...]
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Challenges and perspectives in the biomedical information ecosystem
G. Casino

El profesional de la información (2019). Vol. 28, (2), 72

Abstract
The new information flows and the collapse of the journalistic monopoly in the intermediation with the public, have created opportunities and dysfunctions in biomedical information. To the problems of hype and commercialization, those related to the lack of filters and the diffusion of bad science have been added. This article discusses the challenges posed by these problems and the perspectives in academic research, communication and journalism.
Abstract
The new information flows and the collapse of the journalistic monopoly in the intermediation with the public, have created opportunities and dysfunctions in biomedical information. [...]
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Audiencias activas y discusión social en la esfera pública digital. Artículo de revisión
P. Masip, C. Ruiz-Caballero, J. Suau

El profesional de la información (2019). Vol. 28, (2), 70

Abstract
En poco más de una década, conceptos esenciales de la investigación sobre comunicación se han convertido en conceptos zombis (Beck; Willms, 2004) y no son eficaces para comprender la profunda transformación que se ha producido con la irrupción de internet. Esfera pública, deliberación, audiencias, público... La bibliografía académica ha oscilado entre un optimismo inicial sobre las posibilidades de fortalecimiento de la democracia de las tecnologías de la comunicación a un escepticismo crítico. Este texto revisa la bibliografía académica en relación a las formas de deliberación social adoptadas en el contexto de los medios de comunicación y de las redes sociales y su incidencia en la esfera pública.
Abstract
En poco más de una década, conceptos esenciales de la investigación sobre comunicación se han convertido en conceptos zombis (Beck; Willms, 2004) y no son eficaces para [...]
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Contributions to the formulation to the barquisimeto local urban development plan
G. Fernández

Gaceta Técnica (2019). Vol. 19, 6

Abstract
Barquisimeto, capital del Estado Lara, Venezuela, cuenta con un Plan de Desarrollo Urbano Local aprobado en agosto de 2003 cuya vigencia se estimaba hasta el 2016, razón por la cual las autoridades municipales tienen la responsabilidad de asumir su actualización o la formulación de un nuevo plan que rija el ordenamiento urbanístico de la ciudad por los próximos veinte años. La formulación del plan es una tarea que debe considerar todas las dimensiones que integran el desarrollo de la ciudad dado el imprescindible enfoque multisectorial, requiriendo resolver algunos problemas en la dinámica urbana, así como algunas debilidades del instrumento vigente. A través del presente trabajo se propone un conjunto de ideas sobre aspectos clave que debe abordar el nuevo instrumento, como son: considerar los acuerdos internacionales relativos a los objetivos del desarrollo sostenible y la nueva agenda urbana, el rol de Barquisimeto en la subregión, la integración de las zonas de barrios, la incorporación de Transbarca, la consideración de nuevos centros y dinámicas de empleo, revisar la zonificación, innovar en cuanto a la dotación de equipamientos y la protección del patrimonio edificado, incorporar programas de actuaciones urbanas bajo la perspectiva de los planes estratégicos y, finalmente, la estrategia de instrumentar el plan macro con micro planes. Para lograr el propósito del trabajo, se identifican fuentes de información y experiencias locales, nacionales e internacionales que servirán de referencia al equipo profesional que asuma el reto de diseñar el nuevo Plan de Desarrollo Urbano Local.
Abstract
Barquisimeto, capital del Estado Lara, Venezuela, cuenta con un Plan de Desarrollo Urbano Local aprobado en agosto de 2003 cuya vigencia se estimaba hasta el 2016, razón [...]
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Many changes and some certainties for research and special libraries, and documentation centers
L. Anglada

El profesional de la información (2019). Vol. 28, (1), 68

Abstract
It is argued that despite the many changes being experienced by research and specialized libraries, and documentation centers, which cause them doubts about their future, there are some certainties that allow these centers to properly address their activities. It is proposed to distinguish between minor and profound changes and it is affirmed that, for information centers, the fundamental change has been to go from a situation in which information was scarce and the time to look for it abundant, to another in which time to look for information is scarce and information is abundant. This should help redirect the activities of the information centers -following M. Buckland- to stop focusing on the ‘information- as-an-object’ to concentrate on the ‘information-as-a-process’. Two consolidated movements should help them to guide their future: the Open Science and the Digital Humanities. Some information products that reflect a change in the ways people approach and use information are examined: Museo del Prado’s The Collection, Transcribe Bentham, eBird and Mapa Literari Català. Finally, the author recommends to documentation centers, and specialized and research libraries to guide their services to digitize their heritage collections in an enriched manner, to promote citizen participation, and to create and strengthen communities.
Abstract
It is argued that despite the many changes being experienced by research and specialized libraries, and documentation centers, which cause them doubts about their future, [...]
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Digital journalism: 25 years of research. Review article
R. Salaverría

El profesional de la información (2019). Vol. 28, (1), 66

Abstract
In 1994, the first web online media outlets were introduced in several countries around the world. Twenty-five years later, digital or online journalism is a confirmed reality and common practice in professional and academic circles. Based on an extensive bibliographic review, this article examines the main areas of academic research related to digital media at the global level in the last quarter of a century. It shows the lines of research on the history of journalism on the Internet, the forms of digital media, their languages and economic challenges. It also reviews the most widespread research theories and methods. The analysis confirms that research on digital journalism is a strong, ongoing discipline, despite the fact that several methodological and thematic challenges will need to be addressed in the next few years.
Abstract
In 1994, the first web online media outlets were introduced in several countries around the world. Twenty-five years later, digital or online journalism is a confirmed reality [...]
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Off-page SEO and link building: General strategies and authority transfer in the digital news media
C. Lopezosa, L. Codina, C. Gonzalo-Penela

El profesional de la información (2019). Vol. 28, (1), 64

Abstract
In recent years, a number of digital news media outlets have begun to include paid links in their content. This study seeks to identify and analyse this content whose sole purpose is to improve the website authority of the advertisers and their search engine rankings. To do so, it employs two basic methodologies: first, it undertakes a systematic review of off-page SEO practices, the digital press and native advertising; and, second, it reports a case study based on the identification and analysis of 150 news items that contain specially commissioned links resulting from a commercial transaction. The study provides evidence of a new revenue stream for the digital news media, one that is not clearly disclosed and which is based on the sale of links. The article includes a discussion of the case study findings, and presents future guidelines for the use of paid links based on the emerging concept of ‘native advertising’.
Abstract
In recent years, a number of digital news media outlets have begun to include paid links in their content. This study seeks to identify and analyse this content whose sole [...]
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Digital journalism: 25 years of research. Review article
R. Salaverría

El profesional de la información (2019). Vol. 28, (1), 62

Abstract
In 1994, the first web online media outlets were introduced in several countries around the world. Twenty-five years later, digital or online journalism is a confirmed reality and common practice in professional and academic circles. Based on an extensive bibliographic review, this article examines the main areas of academic research related to digital media at the global level in the last quarter of a century. It shows the lines of research on the history of journalism on the Internet, the forms of digital media, their languages and economic challenges. It also reviews the most widespread research theories and methods. The analysis confirms that research on digital journalism is a strong, ongoing discipline, despite the fact that several methodological and thematic challenges will need to be addressed in the next few years.
Abstract
In 1994, the first web online media outlets were introduced in several countries around the world. Twenty-five years later, digital or online journalism is a confirmed reality [...]
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Evaluation of 'GIS' related tools and their applications in the rivers hydraulic modeling
D. Rodríguez, W. Torrealba, J. Rincón

Gaceta Técnica (2019). Vol. 19, 5

Abstract
The research work presented was carried out with the purpose of evaluating GISWater and HECgeoRAS Geographic Information System (GIS) related tools, which function as a connection node between the HEC-RAS model and the QGIS and ArcGIS software respectively. . Here the conditions of creation of the digital model of the land are leveled, with the purpose of obtaining a final result from a parity of circumstances. The case study chosen to obtain the results was the Quebrada Borure located in the city of Barquisimeto, State of Lara, Venezuela. Once both solutions provided by the HEC-RAS hydraulic modeler were obtained, the correlation between both products was determined, being high, close to the value of the unit, reason why it could be concluded that both tools are applicable in the data processing for the HEC-RAS model, with the advantage that GISWater is a free license and works under the geographic information system QGIS with the same characteristics.
Abstract
The research work presented was carried out with the purpose of evaluating GISWater and HECgeoRAS Geographic Information System (GIS) related tools, which function as a connection [...]
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Semantic enrichment for enhancing LAM data and supporting digital humanities. Review article
M. Zeng

El profesional de la información (2019). Vol. 28, (1), 60

Abstract
With the rapid development of the digital humanities (DH) field, demands for historical and cultural heritage data have generated deep interest the data provided by libraries, archives, and museums (LAMs). In order to enhance LAM data’s quality and discoverability while enabling a self-sustaining ecosystem, “semantic enrichment” becomes a strategy increasingly used by LAMs during recent years. This article introduces a number of semantic enrichment methods and efforts that can be applied to LAM data at various levels, aiming to support deeper and wider exploration and use of LAM data in DH research. The real cases, research projects, experiments, and pilot studies shared in this article demonstrate endless potential for LAM data, whether they are structured, semi-structured, or unstructured, regardless of what types of original artifacts carry the data. Following their roadmaps would encourage more effective initiatives and strengthen this effort to maximize LAM data’s discoverability, use- and reuse-ability, and their value in the mainstream of DH and Semantic Web.
Abstract
With the rapid development of the digital humanities (DH) field, demands for historical and cultural heritage data have generated deep interest the data provided by libraries, [...]
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Scholarly reputation building in the digital age: an activity-specific approach. Review article
E. Herman, D. Nicholas

El profesional de la información (2019). Vol. 28, (1), 58

Abstract
Seeking to understand how today's scholars may, indeed should go about building, maintaining and showcasing their professional reputation, the literature review presented here explores the reputational opportunities available to them in the increasingly open-values based, digital and networked environment of Science 2.0. Using a conceptual framework developed with the help of the European Commission and specifically designed for conducting analytical reviews and audits of the reputational value of scholarly activities, this study, examines in some detail the practices –more than 30 of them- that comprise the present-day scientific undertaking from a reputation-accruing angle.
Abstract
Seeking to understand how today's scholars may, indeed should go about building, maintaining and showcasing their professional reputation, the literature review presented [...]
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Reimagining the academic library: What to do next. Review article
D. Lewis

El profesional de la información (2019). Vol. 28, (1), 56

Abstract
This article reviews the conclusions of the author’s 2016 book, Reimagining the academic library and considers changes in scholarly communication and academic libraries that have taken place since its publication. Recommendations for alterations in the practice of individual libraries are provided. The problem of created integrated community-controlled open infrastructure is considered at length, especially the collective action problem that the library community must overcome.
Abstract
This article reviews the conclusions of the author’s 2016 book, Reimagining the academic library and considers changes in scholarly communication and academic libraries [...]
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La visión de los periodistas sobre la evolución del ecosistema (metafórico) de la comunicación sobre salud y biomedicina
G. Revuelta-de-la-Poza

El profesional de la información (2019). Vol. 28, (2), 54

Abstract
Se analiza la percepción de los periodistas especializados sobre las transformaciones de la comunicación pública de la salud y la biomedicina en España en las dos últimas décadas. Se han realizado 20 entrevistas semiestructuradas. En el análisis se ha utilizado el concepto metafórico de “ecosistema”. Según los entrevistados, los principales cambios “ambientales” han sido tecnológicos (destacan la expansión y diversidad de la información online y los efectos de las redes sociales). Se percibe una multiplicación y diversificación de la “especie-fuentes de información”. Dentro de ésta, han aumentado su visibilidad las fuentes especializadas (investigadores y profesionales sanitarios) y las asociaciones civiles (pacientes y consumidores), pero también emergen “especies oportunistas”, como los promotores de fake-news y de pseudoterapias. Los periodistas de salud, a pesar de reconocer que su “ambiente” laboral ha empeorado y de percibir como amenaza la dependencia respecto al clickbait y al posicionamiento en redes, valoran su profesión con satisfacción.
Abstract
Se analiza la percepción de los periodistas especializados sobre las transformaciones de la comunicación pública de la salud y la biomedicina en España en las dos últimas [...]
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Análisis de la Información de vacunas y antivacunas en RRSS e internet y de los patrones visuales y emocionales de estímulos fake vs. real
U. Cuesta-Cambra, L. Martínez Martínez, J. Niño-González

El profesional de la información (2019). Vol. 28, (2), 52

Abstract
Este trabajo analiza el flujo de información y comunicación de vacunas y antivacunas mediante la monitorización de emisores, grupos, noticias en sites y mensajes en RRSS. También se investigan sus efectos sobre la atención, la emoción y el engagement analizados con Eye Tracking, GSR y Facial Expression respectivamente. Resultados: el flujo de comunicación es inestable, en prensa y sites y de carácter informativo y neutro, frecuentemente con fuentes no profesionales. En RRSS se identifican mensajes y grupos de Facebook antivacuna y se presenta un mapping exploratorio de influencers. El análisis de la evolución temporal de los flujos comunicativos (años 2015 al 2018) mostraron evoluciones positivas: disminuye la tendencia antivacunas. Las respuestas emocionales y el engagement no arrojan diferencias entre vacunas-antivacunas: este importante dato se interpreta en términos de procesamiento por heurísticos. Sorprendentemente, aparecieron diferencias de género en el patrón de exploración de la información y emoción provocada (GSR y Expression).
Abstract
Este trabajo analiza el flujo de información y comunicación de vacunas y antivacunas mediante la monitorización de emisores, grupos, noticias en sites y mensajes en RRSS. [...]
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Applications of blockchain technology in scientific documentation: current situation and perspectives
A. Ferrer-Sapena, E. Sánchez-Pérez

El profesional de la información (2019). Vol. 28, (2), 50

Abstract
Blockchain technology is being introduced in all areas and procedures of verification, identification and recording of the virtual world. Some of its applications are simple translations of methods that are already being developed in other technical supports, but most of them provide new utilities that can change the technological context of scientific documentation. In this article we present an updated panorama of the initiatives based on blockchain for the management of scientific and technological documentation, highlighting those aspects that make this new technology a differentiated and authentically novel tool. A critical analysis with theoretical and practical considerations on its potential use completes the content of this work.
Abstract
Blockchain technology is being introduced in all areas and procedures of verification, identification and recording of the virtual world. Some of its applications are simple [...]
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Do online support groups influence the well-being of patients with diabetes?
N. Herrero, L. Mas-Manchón, F. Guerrero-Solé

El profesional de la información (2019). Vol. 28, (2), 48

Abstract
Diabetes is one of the most challenging long-term diseases (LTD) nowadays. Diabetes is associated with dietary restrictions, medical treatments and a strict life style, and has important emotional implications. The aim of this study is to analyze the impact of participating in online support groups (OSG) and participants’ emotional well-being, social support, self-esteem and motivation. An online survey was disseminated in online forums about diabetes, in Spanish (N = 344). Results show that participating in OSGs has a significant influence on the four variables analyzed. However, the direction of this influence depends on participants’ type of diabetes. Participating in OSG is associated with an increase in self-reported social support and motivation for type 2 patients with diabetes, while it is associated with a decrease of both variables for type 1 patients. No differences were observed for emotional well-being and self-esteem. These results have direct implications for both people with type 1 and 2 diabetes and medical professionals in managing online communications more effectively.
Abstract
Diabetes is one of the most challenging long-term diseases (LTD) nowadays. Diabetes is associated with dietary restrictions, medical treatments and a strict life style, and [...]
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Additive manufacturing technologies for biomedical engineering applications: Research trends and scientific impact
E. Zarrabeitia-Bilbao, I. Alvarez-Meaza, R. Rio-Belver, G. Garechana-Anacabe

El profesional de la información (2019). Vol. 28, (2), 46

Abstract
Additive Manufacturing (AM) technologies, technologies that produce three-dimensional parts layer by layer from a material, have the potential to revolutionize the paradigm of manufacturing. Furthermore, in recent years AM technologies have sparked intense interest for developing medical implants, devices and scaffolds. In this context, the main objective of this article is to present an overall view of the trends and the impact of the research carried out in AM technologies for biomedical engineering applications. Therefore, to achieve the main objective, a research trend and scientific impact analysis model has been designed and implemented, which carries out a bibliometric indicator analysis, in general, and a web indicator analysis, in particular. The findings obtained will advance the means of visualizing the state of research in AM for biomedical engineering technologies.
Abstract
Additive Manufacturing (AM) technologies, technologies that produce three-dimensional parts layer by layer from a material, have the potential to revolutionize the paradigm [...]
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La información importa: narrativa de las webs de las clínicas de fertilidad en España
L. Mohammadi

El profesional de la información (2019). Vol. 28, (2), 44

Abstract
Uno de los hitos más importantes en la tecnología de reproducción asistida es la técnica de preservación del ovocito, la cual permite a las mujeres preservar sus óvulos cuando existe la posibilidad de que pierdan su fertilidad en el futuro. A pesar del estado aún experimental de este procedimiento, las clínicas de fertilidad lo recomiendan ampliamente a mujeres con buena salud que desean posponer la maternidad por razones sociales. Dado que en las webs de las clínicas de fertilidad aparecen numerosas recomendaciones y promociones sobre esta tecnología, parece importante analizar las técnicas de comunicación persuasiva que utilizan a través de internet. Se aplica una metodología mixta de análisis de contenido y análisis de discurso desde la perspectiva de la teoría de los frames. Luego, se realiza un análisis en profundidad del contenido de los webs de las clínicas de fertilidad en España, describiendo sus estrategias de comunicación e información en relación a la preservación de la fertilidad por razones sociales. Los resultados confirman la inconsistencia que existe en la claridad de la información proporcionada por estas webs, dado que la información es estructurada con la intención de atraer a más mujeres a contratar los servicios de congelación de óvulos.
Abstract
Uno de los hitos más importantes en la tecnología de reproducción asistida es la técnica de preservación del ovocito, la cual permite a las mujeres preservar sus óvulos [...]
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Dr. Google, ¿qué me puede decir sobre la homeopatía? Estudio comparativo de las top10 webs en EEUU, Reino Unido, Francia, México y España
L. Cano-Orón

El profesional de la información (2019). Vol. 28, (2), 42

Abstract
El acceso de los usuarios a Google para informarse sobre temas de salud es algo común entre la ciudadanía. Esta investigación analiza los mejores resultados de tres búsquedas genéricas sobre homeopatía, recogidos en cuatro oleadas en cinco países: España, Francia, México, Reino Unido y Estados Unidos. En concreto, se estudia la fluctuación del ranking del corpus y se toma una muestra de las 10 páginas mejor posicionadas en cada país para analizar su contenido (la autoría de la web, la valoración de la efectividad de la homeopatía, la presencia de controversia y el tipo de contenido). Los resultados muestran que el ranking es estable; que la valoración de la homeopatía está vinculada al estado de la opinión pública del país; siendo la mayoría de webs que aparecen mejor posicionadas de noticias publicadas en medios de comunicación.
Abstract
El acceso de los usuarios a Google para informarse sobre temas de salud es algo común entre la ciudadanía. Esta investigación analiza los mejores resultados de tres búsquedas [...]
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Health information: Media sources and professional challenges
M. Saavedra-LLamas, M. Herrero-De-la-Fuente, L. Rodríguez-Fernández, C. Jiménez-Narros

El profesional de la información (2019). Vol. 28, (2), 40

Abstract
Journalists specialized in health information have changed their work routines because of Internet and social networks. Generating health content allows researchers, physicians and patients to be connected and, in this respect, media play a prescriber role in the society. In this paper, the prevailing precariousness in the media is analyzed in order to see if it affects health information and the specialization of its professionals. This work is based on a qualitative research, using in-depth interviews with health information journalists belonging to 16 Spanish media. The research underscores the priority of certain resources, the need to enable verification processes and to face new professional challenges. This research is part of the Aula Nebrija-MSD Spain of Communication and Health Sciences funded project.
Abstract
Journalists specialized in health information have changed their work routines because of Internet and social networks. Generating health content allows researchers, physicians [...]
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Diseño de un Plan de Social Media en salud a través de metodología participativa. Evaluación de la experiencia del Hospital Reina Sofía
M. López-Doblas, O. Pérez-Corral, D. Gómez-Domínguez, A. Danet-Danet

El profesional de la información (2019). Vol. 28, (2), 38

Abstract
Se presenta una metodología participativa para el diseño del Plan de Social Media (PSM) para organizaciones sanitarias, así como la evaluación de la experiencia en el Hospital Reina Sofía. La metodología de diseño colaborativo y multidisciplinar se desarrolló en cinco fases: identificación de agentes claves; consenso sobre objetivos, públicos, canales y líneas de contenido; análisis y devolución de resultados; diseño de (pre)campaña; elaboración colaborativa del PSM. La evaluación se realizó a través de monitorización de presencia en redes (evaluación cuantitativa de la comunicación externa) y análisis de contenido de entrevistas semiestructuradas al equipo directivo (evaluación cualitativa de la comunicación interna). Los resultados reflejan el impacto positivo en comunicación externa y la satisfacción con la metodología de co-diseño, evidenciando la importancia de la participación profesional y de la interdisciplinariedad, así como del apoyo directivo y de la profesionalización para la planificación de presencia en redes en el ámbito hospitalario.
Abstract
Se presenta una metodología participativa para el diseño del Plan de Social Media (PSM) para organizaciones sanitarias, así como la evaluación de la experiencia en el [...]
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Specialty matters. Analysis of health journalists’ coverage about vaccines
D. Catalán-Matamoros, C. Peñafiel-Saiz

El profesional de la información (2019). Vol. 28, (2), 36

Abstract
This study examines specific professional patterns among health journalists, and assesses whether these differ from those among generalists in the case of vaccines. 131 articles were analysed from national newspapers in Spain, of which 52% (n=68) were written by specialised health journalists. Content analysis was undertaken to examine the differences in terms of journalistic genre, frames, tone, sources and length of the article. Results revealed key journalistic patterns and confirmed that health journalists perform significantly differently than other authors in terms of journalistic genre, tone, sources and length of the article. Health journalists wrote more features and less opinion articles, from a more neutral perspective, using a wider number of scientific sources, especially those from professional associations and scientific journals. These findings provide insights into the process of health journalism, and identify potential aspects to further develop the profession for the broad dissemination of health news to the public.
Abstract
This study examines specific professional patterns among health journalists, and assesses whether these differ from those among generalists in the case of vaccines. 131 articles [...]
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Technical and economic analysis of design for performance of buildings with steel structure using concentric bracings
D. Cuasapaz

Gaceta Técnica (2019). Vol. 19, 3

Abstract
This paper presents the analysis of ten structural models of steel structure buildings, using different lateral concentric arches, with software Etabs-16 and Sap2000. to make an observation of the results obtained from the linear and non-linear analysis (Pushover) of the models; taking into consideration the compliance with the minimum parameters established in the Ecuadorian Construction Standard NEC-15, regarding the evaluation of the basal shear and controls so that the structures are considered seismic resistant. The definitive designs of the steel structures are obtained considering the American Institute of Steel Construction norm, and based on the summaries of materials in which indexes are detailed between the total weight and the area of the structures, reference budgets were elaborated. As a consequence, an economic evaluation was carried out to determine which type of concentric bracing turns out to be the most beneficial in terms of costs. The results obtained indicate that the most economical concentric bracing alternative corresponds to the use of reinforced concrete cutting walls, in which savings can be obtained ranging from 14,18% to 17,34% with the use of the other bracing alternatives.
Abstract
This paper presents the analysis of ten structural models of steel structure buildings, using different lateral concentric arches, with software Etabs-16 and Sap2000. to make [...]
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Privacy paradox in mobile environments: The influence of the emotions
F. Sarabia-Sánchez, J. Aguado, I. Martínez-Martínez

El profesional de la información (2019). Vol. 28, (2), 34

Abstract
The increasing relevance of personal information has sparked a broad debate on privacy issues on the ubiquitous Internet. The so called ‘privacy paradox’ aims to explain through rational decision-making models the contradictions between stated digital privacy concerns and the actual behaviors in mobile platforms. An analysis of the emotions that arise when users know about unauthorized personal data disclosure is proposed. A survey of smartphone users was conducted shortly after the Cambridge Analytica / Facebook scandal took place, in order to analyze the nature and intensity of a user’s emotions in relation to their knowledge of privacy breaches. The results support the paradox of privacy from an emotional perspective: although the reported emotions are intense, there is no relationship between the management that users make of their privacy settings in social networks and mobile applications and the nature and intensity of the emotions reported.
Abstract
The increasing relevance of personal information has sparked a broad debate on privacy issues on the ubiquitous Internet. The so called ‘privacy paradox’ aims to explain [...]
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Ética en la publicación científica biomédica. Una revisión de las publicaciones retractadas en España.
G. Marco-Cuenca, J. Salvador-Oliván, R. Arquero-Avilés

El profesional de la información (2019). Vol. 28, (2), 32

Abstract
El presente estudio identifica las principales causas de retractación de artículos de autores afiliados en España, así como otros factores que ayudan a interpretar este fenómeno en el contexto definido. Se han analizado un total de 132 retractaciones, siendo la primera causa de retractación la fabricación y/o falsificación de datos. También destacan las causas asociadas a imágenes duplicadas o reutilizadas, los errores en los datos y/o procedimientos admitidos y no malintencionados, los artículos duplicados o fragmentados y el plagio. Las retractaciones no son frecuentes y suponen solamente el 0,11% de la producción de autores con afiliación en España. Pero mucho más allá, las retractaciones son un importante mecanismo de corrección y alerta para las publicaciones científicas que asegura la fiabilidad de la literatura médica, su calidad y progreso.
Abstract
El presente estudio identifica las principales causas de retractación de artículos de autores afiliados en España, así como otros factores que ayudan a interpretar este [...]
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Reputation and scientific communication: Early career researchers in Spain
B. Rodríguez-Bravo, D. Nicholas

El profesional de la información (2019). Vol. 28, (2), 30

Abstract
The situation of Spanish early career researchers is investigated based on the results obtained from the international project: Early career researchers: The harbingers of change? It is about knowing what are their habits in scientific communication, what role do the developments of Science 2.0 play in their behaviour and to what extent the indicators of evaluation of their activity are decisive in their attitudes and practices. It is concluded that these researchers have the aptitudes and the will to promote change but are hampered by the conservatism of the requirements of evaluation of the scholar communication at the academia.
Abstract
The situation of Spanish early career researchers is investigated based on the results obtained from the international project: Early career researchers: The harbingers of [...]
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Adoption of social media by social sciences scientific journals
C. Arcila-Calderón, M. Calderín-Cruz, P. Sánchez-Holgado

El profesional de la información (2019). Vol. 28, (1), 28

Abstract
The expansion of social media forces the communication of science and scientific journals to adapt to this new environment. Previous studies and theoretical models such as Utaut and Utaut2 have proven that there is a relationship between the perception of future performance of technology (performance expectancy), the difficulty of use (effort expectancy) and the social influence to which the individual is subject, on the real use of technology, but there is still scarce research about the mechanisms that cause this effect. Starting with Utaut, the hypothesis is that there is an indirect conditional effect of the performance expectancy, the effort expectancy and social influence, over the actual use of social media in scientific journals, where the effect is driven through the intention of use and the size of the effect is moderated by gender and age. A survey was carried out on 300 editors of the top 20 in Social Sciences of the Google Scholar ranking. Confirming partially Utaut, the results of moderated mediation show that performance expectancy and social influence of editors affect the use of Facebook and Twitter, through the intention to use, but it is not the case of ResearchGate, Academia and LinkedIn. There is not enough evidence about the moderation of age and gender.
Abstract
The expansion of social media forces the communication of science and scientific journals to adapt to this new environment. Previous studies and theoretical models such as [...]
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La supresión de anuncios de contactos sexuales autorregulación, legislación o colaboración institucional
F. Martínez-Vallvey, A. Mellado-Segado

El profesional de la información (2019). Vol. 28, (2), 26

Abstract
Las dos principales fuentes de financiación de la prensa son las ventas de ejemplares al público y la venta de espacios publicitarios a los anunciantes. Un tipo específico de publicidad es la denominada “anuncios por palabras”, entre los que se encuentran los anuncios de “contactos sexuales”. En los últimos años su presencia en los diarios de España ha disminuido, a pesar de la falta de códigos éticos que limiten su presencia en las páginas y a que los diferentes gobiernos no han podido acometer una legislación que impida su publicación. El respeto a los derechos humanos de las mujeres, la lucha contra la trata y explotación de ésta obliga a que esta práctica desaparezca, a pesar de la pérdida de ingresos que pueda suponer para una empresa periodística.
Abstract
Las dos principales fuentes de financiación de la prensa son las ventas de ejemplares al público y la venta de espacios publicitarios a los anunciantes. Un tipo específico [...]
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Testimonials in health-related radio advertising in Spain and their regulation (2009-2016)
S. Perelló-Oliver, C. Muela-Molina, M. Campos-Zabala

El profesional de la información (2019). Vol. 28, (2), 24

Abstract
The objective of this work is to analyze the nature of testimonials that advertise products with alleged health benefits, the testimonial characteristics and the evolution in Spanish radio. The study of quantitative and multistage nature is based on the content analysis of radio spots from two different time samples: 1,664 spots in 2009 and 3,909 in 2016 which, after the required data filtering process, were reduced to 147 and 122 testimonials, respectively. One of the implications derived from this work is that the public administration should improve the monitoring and control of illicit advertising that involves health-related products. The media itself should implement advertising protocols that include prior review and self-regulation.
Abstract
The objective of this work is to analyze the nature of testimonials that advertise products with alleged health benefits, the testimonial characteristics and the evolution [...]
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The social construction of the image of a city through Instagram: The case of Granada
F. Cantón-Correa, J. Alberich-Pascual

El profesional de la información (2019). Vol. 28, (1), 22

Abstract
Our digital world is increasingly visual. Mobile applications focused on digital photography such as Instagram are vehicles for the creation, manipulation and instant diffusion of images. Instagram is therefore an open window to research in Social Sciences and Digital Humanities, and an opportunity to investigate how young users of this application develop visual culture in their local environments through global visual languages. The present work analyzes the production of Instagram in Granada from a sample of 955.564 publications and 375.758 images published and geolocated over a year (between April 2017 and April 2018), with the aim of showing how the image of a city is socially constructed. The geographical, social network, and content analysis of the study sample has allowed to establish which are the main focal points of visual attraction of the city, as well as the most active neighborhoods and districts; the most relevant members of a user network that is self-constructed in a heterogeneous and open manner, with strong intermediary nodes of an “instagramist” style that connect subcommunities; as well as the widespread use of the application both for business promotion and for the development of individual creativity. All this indicates how the Instagram publications in Granada make visible the importance and incidence of tourism in the city.
Abstract
Our digital world is increasingly visual. Mobile applications focused on digital photography such as Instagram are vehicles for the creation, manipulation and instant diffusion [...]
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Sci-Hub, challenge for academic and research libraries
L. González-Solar, V. Fernández-Marcial

El profesional de la información (2019). Vol. 28, (1), 20

Abstract
Sci-Hub breaks into the field of scientific communication in 2011 as a platform for free access to scientific papers. It is the most popular of the so-called shadow libraries, systems that overcome the limits of legal access to scientific publications, standing outside the open access movement. Apart from the media issues that have made it gain popularity, several studies reveal the Sci-Hub impact among researchers, who have accepted this initiative willingly. Sci-Hub has revealed new forms of access to scientific information, affecting academic and research libraries that cannot remain on the sidelines. This study addresses the Sci-Hub phenomenon and its implications for academic and research libraries from different points of view, through a bibliographic review and the analysis of examples of action.
Abstract
Sci-Hub breaks into the field of scientific communication in 2011 as a platform for free access to scientific papers. It is the most popular of the so-called shadow libraries, [...]
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Entre broadcast yourself y broadcast whatever: la página de inicio de YouTube como síntesis de su estrategia empresarial
M. De-Aguilera-Moyano, A. Castro-Higueras, J. Pérez-Rufí

El profesional de la información (2019). Vol. 28, (2), 18

Abstract
YouTube es una empresa representativa de su contexto originario, la web 2.0, posicionándose como plataforma abierta y colaborativa para difundir vídeos de todo tipo de usuario, con el slogan Broadcast yourself. La adquisición de YouTube por Google la introduce en la búsqueda de beneficios en el marco de la comunicación OTT (over the top). La página de inicio de YouTube muestra las sucesivas políticas empresariales de la plataforma. Se analiza la evolución de la página de inicio no logueada de YouTube España entre 2009 y 2018. Se observa la gradual desaparición de los vídeos producidos por usuarios particulares y su sustitución por los vídeos de usuarios profesionalizados (youtubers) y de industrias culturales. Hay un notable paralelismo entre la implementación de modelos de negocio y la mayor o menor recomendación de vídeos de uno u otro tipo.
Abstract
YouTube es una empresa representativa de su contexto originario, la web 2.0, posicionándose como plataforma abierta y colaborativa para difundir vídeos de todo tipo de usuario, [...]
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La salud en el debate online: análisis de comentarios sobre carnes rojas y procesadas y cáncer en el elpais.com
C. González-Pedraz, A. Pérez-Rodríguez

El profesional de la información (2019). Vol. 28, (2), 16

Abstract
En Internet, el lector puede participar en la información periodística a través de los comentarios, que se han convertido en una interesante fuente de datos para analizar la opinión de las audiencias sobre la actualidad científica y sanitaria. El presente trabajo realiza un análisis de contenido cuantitativo y cualitativo de un corpus de 2394 comentarios a noticias sobre la relación entre carnes rojas y procesadas y cáncer en elpais.com. Los comentarios no parecen contribuir a una versión más completa del reporte periodístico, sino que el debate se desvirtúa en gran medida hacia otros asuntos. Los comentaristas se basan en su experiencia personal y en estereotipos para rechazar la evidencia científica.
Abstract
En Internet, el lector puede participar en la información periodística a través de los comentarios, que se han convertido en una interesante fuente de datos para analizar [...]
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Digital public engagement in excellent Spanish Science: Analysis of research projects funded by European Research Council
L. López-Pérez, M. Olvera-Lobo

El profesional de la información (2019). Vol. 28, (1), 14

Abstract
How much the excellent science uses web 2.0 tools to encourage public engagement in the research process is analyzed. Understanding participation, from the perspective of responsible research and innovation, not only as the communication of scientific results, but also the involvement of society in scientific development. For the analysis, an ad-hoc questionnaire developed using the Delphi method was designed and validated. The study sample is constituted by Spanish projects financed by the European Research Council in 2015. Among the results obtained, the reduced use of digital applications stands out. In fact, only 23.9% of projects have a website and less than 15% have a social profile. Regarding participation mechanisms, a limited 3% uses web 2.0 to involve citizens. With reference to the characteristics of the communication, it can be concluded that it is unidirectional from the institution responsible for the project to society -97% of the cases- and presents a high level of specialization -in more than 80% of the cases a technical language is used and the messages posted are aimed solely at experts-.
Abstract
How much the excellent science uses web 2.0 tools to encourage public engagement in the research process is analyzed. Understanding participation, from the perspective of [...]
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Estudio longitudinal sobre el tratamiento de la homeopatía en la prensa digital española (2012-2016)
V. Roger-Monzó, M. Martí-Sánchez

El profesional de la información (2019). Vol. 28, (2), 12

Abstract
El objetivo de este estudio es evaluar cómo la prensa digital española aborda las informaciones relativas a la homeopatía. Para llevar a cabo la investigación, se ha desarrollado un análisis de contenido de los artículos publicados sobre homeopatía entre 1 de enero de 2012 y 31 de diciembre de 2016 en los tres diarios digitales de información general y ámbito nacional más leídos: El Mundo, El País y ABC. La búsqueda ha recuperado 115 artículos. Los resultados revelan que la noticia es el género informativo más empleado, prevaleciendo el enfoque de controversia y conflicto como encuadre principal. Se antepone el valor noticia de impacto frente al análisis del fenómeno y de sus riesgos para la salud.
Abstract
El objetivo de este estudio es evaluar cómo la prensa digital española aborda las informaciones relativas a la homeopatía. Para llevar a cabo la investigación, se ha desarrollado [...]
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Spanish television fiction since deregulation: Between atomization and vertical concentration of production
C. Lacalle, M. Sánchez-Ares

El profesional de la información (2019). Vol. 28, (1), 10

Abstract
This article attempts to mitigate the absence of data and empirical research on the different types of production of Spanish television fiction, from the initial predominance of in-house production to the near complete industry wide trend of outsourcing. The sample includes 490 productions aired on national networks between 1990 and 2017 across 234 production houses. The research reveals that more than 60% of independent producers have partaken in only one production, while 10 studios (including the three major national networks) are responsible for more than half of the productions. The analysis highlights the paradoxical nature of a sector whose growing specialization and vertical concentration coexists with the atomization of independent producers.
Abstract
This article attempts to mitigate the absence of data and empirical research on the different types of production of Spanish television fiction, from the initial predominance [...]
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Indirect taxation of the book in Europe: Implications and policies
M. Magadán-Díaz, J. Rivas-García

El profesional de la información (2019). Vol. 28, (1), 8

Abstract
The main goal of this study is to determine the role of indirect taxation in the Spanish publishing industry. The work includes: a) a tax treatment comparison of books in Spain with respect to the rest of European countries; b) an evaluation of the options for exemption or reduction of the value added tax (VAT) applied to books; and c) an analysis of book fixed-price policy applied in Europe. The conclusions of this work point, firstly, to the need to harmonize VAT in the EU space; secondly, to reduce tax discrimination between formats and, thirdly, to emphasize that indirect taxation could be converted, if it is not already, in a brake for the development of the digitization of the Spanish publishing industry.
Abstract
The main goal of this study is to determine the role of indirect taxation in the Spanish publishing industry. The work includes: a) a tax treatment comparison of books in [...]
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From flow to stock: The radio programmer facing the management of the digital catalog
M. Bonet, T. Sellas

El profesional de la información (2019). Vol. 28, (1), 6

Abstract
Beyond the undoubted revival of the podcast, its presence in the offer of some Spanish radio stations deserves a detailed analysis. This study presents the analysis of this offer, as well as an approach to the challenges and questions behind the production of native podcasts, exclusively for web consumption. People ultimately responsible for radio programming has to deal with the traditional program schedule, in flow, and now has to add the management of a catalog of podcasts. The quantitative analysis is combined with the qualitative analysis through interviews with some of the top managers responsible for deciding how these two complementary radio offers should coexist. Results show that so far podcasts could be defined as a cultural product rather than a product of a cultural industry.
Abstract
Beyond the undoubted revival of the podcast, its presence in the offer of some Spanish radio stations deserves a detailed analysis. This study presents the analysis of this [...]
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Off-page SEO and link building: General strategies and authority transfer in the digital news media
C. Lopezosa, L. Codina, C. Gonzalo-Penela

El profesional de la información (2019). Vol. 28, (1), 4

Abstract
In recent years, a number of digital news media outlets have begun to include paid links in their content. This study seeks to identify and analyse this content whose sole purpose is to improve the website authority of the advertisers and their search engine rankings. To do so, it employs two basic methodologies: first, it undertakes a systematic review of off-page SEO practices, the digital press and native advertising; and, second, it reports a case study based on the identification and analysis of 150 news items that contain specially commissioned links resulting from a commercial transaction. The study provides evidence of a new revenue stream for the digital news media, one that is not clearly disclosed and which is based on the sale of links. The article includes a discussion of the case study findings, and presents future guidelines for the use of paid links based on the emerging concept of ‘native advertising’.
Abstract
In recent years, a number of digital news media outlets have begun to include paid links in their content. This study seeks to identify and analyse this content whose sole [...]
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Evolución del uso del hipertexto en la prensa española (2002-2016)
P. Orero, B. Cebrián-Enrique

El profesional de la información (2019). Vol. 28, (2), 2

Abstract
Se presentan los resultados del análisis de la evolución del uso del hipertexto en la prensa digital española. Dos décadas después de la aparición de las primeras ediciones web de los diarios españoles, se estudia el grado de madurez, los cambios y las tendencias en el empleo de los enlaces semánticos. Para lograr este objetivo, se realiza un análisis empírico longitudinal retrospectivo de la utilización del hipertexto en la práctica profesional entre los años 2002 y 2016 a través de las hemerotecas digitales de seis cabeceras generalistas. El estudio de periódicos de referencia en la prensa española se complementa con medios de ámbito local, apenas observados en las investigaciones sobre hipertexto hasta ahora realizadas. En total, se examinan 22296 enlaces semánticos que aparecen en 4620 noticias publicadas en portada y se estudian en profundidad los 4830 vínculos incluidos en el cuerpo o relato informativo.
Abstract
Se presentan los resultados del análisis de la evolución del uso del hipertexto en la prensa digital española. Dos décadas después de la aparición de las primeras ediciones [...]
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Elastoplastic behavior of welded connections in square section steel pipes submitted to monotonic load
C. Romero, A. Portillo

Gaceta Técnica (2019). Vol. 19, 2

Abstract
This research aims to analyze the elastoplastic behavior of welded connections of square section steel tubes subjected to monotonic loading, by means of the theoretical - experimental comparative analysis of the distortion of the cross section geometry of the elements of the beam - column joint. For the experimental tests it was necessary to build a rigid support frame designed with STAAD software. Pro v8i, of fixing and assembly to the gantries and load application system of the universal machine of the Materials Laboratory of the Faculty of Engineering of the University of Zulia. In every test a progressive load (monotonic load) was applied on the upper connection of the gantry to systematically to measure displacements and distortion of the geometry of the beam jointing elements column of the lower connection. While the theoretical model was performed using the finite element program [4] ANSYS Workbench. The obtained results show that: the welded connection presents a local failure by punching in the column that reduces the theoretical plastic moment capacity of the gantry "Mp" by 46%, scenario of concern for being this capacity used in the design under the theory Design for Load and Resistance Factors (LRFD). The welded connection (node) does not meet the weak beam strong column criterion established by Norma. The column of the welded joint must be reinforced to avoid the formation of the plastic ball joint and a possible mechanism of collapse in the gantry.
Abstract
This research aims to analyze the elastoplastic behavior of welded connections of square section steel tubes subjected to monotonic loading, by means of the theoretical - [...]
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3D numerical models of FSW processes with non-cylindrical pin
P. Bussetta, N. Dialami, M. Chiumenti, C. Agelet de Saracibar, M. Cervera, J. Ponthot

Advances in Materials and Processing Technologies (2016). (preprint) Vol. 1 (3-4), pp. 275-287

Abstract
Friction stir welding (FSW) process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are not melted. During the FSW process, the behaviour of the material is at the interface between solid mechanics and fluid mechanics. In this paper, a 3D numerical model of the FSW process with a non-cylindrical tool based on a solid formulation is compared to another one based on a fluid formulation. Both models use advanced numerical techniques such as the arbitrary Lagrangian–Eulerian formulation, remeshing or the orthogonal sub-grid scale method. It is shown that these two formulations essentially deliver the same results.
Abstract
Friction stir welding (FSW) process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are [...]
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A crack-tracking technique for localized cohesive-frictional damage
S. Saloustros, L. Pelà, M. Cervera

Engineering Fracture Mechanics (2015). (preprint) Vol. 150, pp. 96-114

Abstract
This paper extends the use of crack-tracking techniques within the smeared crack approach for the numerical simulation of cohesive–frictional damage on quasi-brittle materials. The mechanical behaviour is described by an isotropic damage model with a Mohr–Coulomb failure surface. The correct crack propagation among the two alternative fracture planes proposed by the Mohr–Coulomb theory is selected with the use of an energy criterion based on the total elastic strain energy. The simulation of three benchmark problems of mixed-mode fracture in concrete demonstrates that the proposed methodology can reproduce the material’s frictional characteristics, showing robustness, as well as mesh-size and mesh-bias independence.
Abstract
This paper extends the use of crack-tracking techniques within the smeared crack approach for the numerical simulation of cohesive–frictional damage on quasi-brittle [...]
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3D numerical models of FSW processes with non-cylindrical pin
P. Bussetta, N. Dialami, M. Chiumenti, C. Agelet de Saracibar, M. Cervera, R. Boman, J. Ponthot

Advanced Modeling and Simulation in Engineering Sciences (2015). (preprint) Vol. 2 (27), pp. 1-19

Abstract
Friction stir welding process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are not melted. During the FSW process, the behaviour of the material is at the interface between solid mechanics and fluid mechanics. In this paper, a 3D numerical model of the FSW process with a non-cylindrical tool based on a solid formulation is compared to another one based on a fluid formulation. Both models use advanced numerical techniques such as the Arbitrary Lagrangian Eulerian formulation, remeshing or the Orthogonal Sub-Grid Scale method. It is shown that these two formulations essentially deliver the same results.
Abstract
Friction stir welding process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are not melted. [...]
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On the equivalence between traction- and stress-based approaches for the modeling of localized failure in solids
J. Wu, M. Cervera

Journal of the Mechanics and Physics of Solids (2015). (preprint) Vol. 82, pp. 137-163

Abstract
This work investigates systematically traction- and stress-based approaches for the modeling of strong and regularized discontinuities induced by localized failure in solids. Two complementary methodologies, i.e., discontinuities localized in an elastic solid and strain localization of an inelastic softening solid, are addressed. In the former it is assumed a priori that the discontinuity forms with a continuous stress field and along the known orientation. A traction-based failure criterion is introduced to characterize the discontinuity and the orientation is determined from Mohr's maximization postulate. If the displacement jumps are retained as independent variables, the strong/regularized discontinuity approaches follow, requiring constitutive models for both the bulk and discontinuity. Elimination of the displacement jumps at the material point level results in the embedded/smeared discontinuity approaches in which an overall inelastic constitutive model fulfilling the static constraint suffices. The second methodology is then adopted to check whether the assumed strain localization can occur and identify its consequences on the resulting approaches. The kinematic constraint guaranteeing stress boundedness and continuity upon strain localization is established for general inelastic softening solids. Application to a unified stress-based elastoplastic damage model naturally yields all the ingredients of a localized model for the discontinuity (band), justifying the first methodology. Two dual but not necessarily equivalent approaches, i.e., the traction-based elastoplastic damage model and the stress-based projected discontinuity model, are identified. The former is equivalent to the embedded and smeared discontinuity approaches, whereas in the later the discontinuity orientation and associated failure criterion are determined consistently from the kinematic constraint rather than given a priori. The bi-directional connections and equivalence conditions between the traction- and stress-based approaches are classified. Closed-form results under plane stress condition are also given. A generic failure criterion of either elliptic, parabolic or hyperbolic type is analyzed in a unified manner, with the classical von Mises (J2), Drucker–Prager, Mohr–Coulomb and many other frequently employed criteria recovered as its particular cases.
Abstract
This work investigates systematically traction- and stress-based approaches for the modeling of strong and regularized discontinuities induced by localized failure in [...]
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On the conformity of strong, regularized, embedded and smeared discontinuity approaches for the modeling of localized failure in solids
M. Cervera, J. Wu

Int. J. Solids and Structures (2015). (preprint) Vol. 71 (1), pp. 19-38

Abstract
Once strain localization occurs in softening solids, inelastic loading behavior is restricted within a narrow band while the bulk unloads elastically. Accordingly, localized failure in solids can be approached by embedding or smearing a traction-based inelastic discontinuity (band) within an (equivalent) elastic matrix along a specific orientation. In this context, the conformity of the strong/regularized and embedded/smeared discontinuity approaches are investigated, regarding the strategies dealing with the kinematics and statics. On one hand, the traction continuity condition imposed in weak form results in the strong and regularized discontinuity approaches, with respect to the approximation of displacement and strain discontinuities. In addition to the elastic bulk, consistent plastic-damage cohesive models for the discontinuities are established. The conformity between the strong discontinuity approach and its regularized counterpart is shown through the fracture energy analysis. On the other hand, the traction continuity condition can also be enforced point-wisely in strong form so that the standard principle of virtual work applies. In this case, the static constraint resulting from traction continuity can be used to eliminate the kinematic variable associated with the discontinuity (band) at the material level. This strategy leads to embedded and smeared discontinuity models for the overall weakened solid which can also be cast into the elastoplastic degradation framework with a different kinematic decomposition. Being equivalent to the kinematic constraint guaranteeing stress continuity upon strain localization, Mohr’s maximization postulate is adopted for the determination of the discontinuity orientation. Closed-form results are presented in plane stress conditions, with the classical Rankine, Mohr–Coulomb, von Mises and Drucker–Prager criteria as illustrative examples. The orientation of the discontinuity (band) and the stress-based failure criteria consistent with the given traction-based counterparts are derived. Finally, a generic failure criterion of either elliptic, parabolic or hyperbolic type, appropriate for the modeling of mixed-mode failure, is analyzed in a unified manner. Furthermore, a novel method is proposed to calibrate the involved mesoscopic parameters from available macroscopic test data, which is then validated against Willam’s numerical test.
Abstract
Once strain localization occurs in softening solids, inelastic loading behavior is restricted within a narrow band while the bulk unloads elastically. Accordingly, localized [...]
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Material flow visualization in Friction Stir Welding via particle tracing
N. Dialami, M. Chiumenti, M. Cervera, C. Agelet de Saracibar, J. Ponthot

Int. J. of Material Forming (2015). (preprint) Vol. 8 (2), pp. 167-181

Abstract
This work deals with the modeling of the material flow in Friction Stir Welding (FSW) processes using particle tracing method. For the computation of particle trajectories, three accurate and computationally efficient integration methods are implemented within a FE model for FSW process: the Backward Euler with Sub-stepping (BES), the 4-th order Runge–Kutta (RK4) and the Back and Forth Error Compensation and Correction (BFECC) methods. Firstly, their performance is compared by solving the Zalesak’s disk benchmark. Later, the developed methodology is applied to some FSW problems providing a quantitative 2D and 3D view of the material transport in the process area. The material flow pattern is compared to the experimental evidence.
Abstract
This work deals with the modeling of the material flow in Friction Stir Welding (FSW) processes using particle tracing method. For the computation of particle trajectories, [...]
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Explicit mixed strain-displacement finite element for dynamic geometrically non-linear solid mechanics
N. Lafontaine, R. Rossi, M. Cervera, M. Chiumenti

Computational Mechanics (2015). (preprint) Vol. 55 (3), pp. 543-559

Abstract
Low-order finite elements face inherent limitations related to their poor convergence properties. Such difficulties typically manifest as mesh-dependent or excessively stiff behaviour when dealing with complex problems. A recent proposal to address such limitations is the adoption of mixed displacement-strain technologies which were shown to satisfactorily address both problems. Unfortunately, although appealing, the use of such element technology puts a large burden on the linear algebra, as the solution of larger linear systems is needed. In this paper, the use of an explicit time integration scheme for the solution of the mixed strain-displacement problem is explored as an alternative. An algorithm is devised to allow the effective time integration of the mixed problem. The developed method retains second order accuracy in time and is competitive in terms of computational cost with the standard irreducible formulation.
Abstract
Low-order finite elements face inherent limitations related to their poor convergence properties. Such difficulties typically manifest as mesh-dependent or excessively stiff [...]
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Stress-accurate Mixed FEM for soil failure under shallow foundations involving strain localization in plasticity
L. Benedetti, M. Cervera, M. Chiumenti

Computers and geotechnics (2015). (preprint) Vol. 64, pp. 32-47

Abstract
The development of slip lines, due to strain localization, is a common cause for failure of soil in many circumstances investigated in geotechnical engineering. Through the use of numerical methods – like finite elements – many practitioners are able to take into account complex geometrical and physical conditions in their analyses. However, when dealing with shear bands, standard finite elements display lack of precision, mesh dependency and locking. This paper introduces a (stabilized) mixed finite element formulation with continuous linear strain and displacement interpolations. Von Mises and Drucker–Prager local plasticity models with strain softening are considered as constitutive law. This innovative formulation succeeds in overcoming the limitations of the standard formulation and provides accurate results within the vicinity of the shear bands, specifically without suffering from mesh dependency. Finally, 2D and 3D numerical examples demonstrate the accuracy and robustness in the computation of localization bands, without the introduction of additional tracking techniques as usually required by other methods.
Abstract
The development of slip lines, due to strain localization, is a common cause for failure of soil in many circumstances investigated in geotechnical engineering. Through the [...]
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A localized mapped damage model for orthotropic materials
L. Pelà, M. Cervera, S. Oller, M. Chiumenti

Engineering Fracture Mechanics (2014). (preprint) Vol. 124-125, pp. 196-216

Abstract
This paper presents an implicit orthotropic model based on the Continuum Damage Mechanics isotropic models. A mapping relationship is established between the behaviour of the anisotropic material and that of an isotropic one. The proposed model is used to simulate the failure loci of common orthotropic materials, such as masonry, fibre-reinforced composites and wood. The damage model is combined with a crack-tracking technique to reproduce the propagation of localized cracks in the discrete FE problem. The proposed numerical model is used to simulate the mixed mode fracture in masonry members with different orientations of the brick layers.
Abstract
This paper presents an implicit orthotropic model based on the Continuum Damage Mechanics isotropic models. A mapping relationship is established between the behaviour of [...]
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Analysis of a joint base plate between concrete column-steel columns in the non-linear range
N. López, R. Ugel, R. Herrera

Gaceta Técnica (2019). Vol. 19, 1

Abstract
In this research the behavior of a real scale experimental joint (column-beam joint) formed by three reinforced concrete elements, 1 column and 2 beams, attached to a structural steel column in the upper level is studied. The object in question was subjected to the action of cyclic loads in a single direction, in a pseudostatic test for 5000 s, in order to observe which element of the concrete cylinders failed and which the failure mode was. A mathematical model was created in the ABAQUS CAE software, in order to verify that the design of the gasket of the test piece complied with the normative requirements for the design of base plates, based on concrete crushing and thickness of the base plate. In the bolts its resistance to shear forces, tensile deformation, and verification by tensile cone in the concrete and tensile stress within the cracked area was verified, and it was obtained as a result that the failure was produced by cracking of the reinforced concrete.
Abstract
In this research the behavior of a real scale experimental joint (column-beam joint) formed by three reinforced concrete elements, 1 column and 2 beams, attached to a structural [...]
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Computational Modeling and Sub-Grid Scale Stabilization of Incompressibility and Convection in the Numerical Simulation of Friction Stir Welding Processes
C. Agelet de Saracibar, M. Chiumenti, M. Cervera, N. Dialami, A. Seret

Archives of Comp. Meths. Engng. (2014). (preprint) Vol. 21 (1), pp. 3-37

Abstract
This paper deals with the computational modeling and sub-grid scale stabilization of incompressibility and convection in the numerical simulation of the material flow around the probe tool in a friction stir welding (FSW) process. Within the paradigmatic framework of the multiscale stabilization methods, suitable pressure and convective derivative of the temperature sub-grid scale stabilized coupled thermomechanical formulations have been developed using an Eulerian description. Norton-Hoff and Sheppard-Wright thermo-rigid-viscoplastic constitutive material models have been considered. Constitutive equations for the sub-grid scale models have been proposed and an approximation of the sub-grid scale variables has been given. In particular, algebraic sub-grid scale (ASGS) and orthogonal sub-grid scale (OSGS) methods for mixed velocity, pressure and temperature P1/P1/P1 linear elements have been considered. Furthermore, it has been shown that well known classical stabilized formulations, such as the Galerkin least-squares (GLS) for incompressible (or quasi-incompressible) problems or the Streamline Upwind/Petrov-Galerkin (SUPG) method for convection dominant problems, can be recovered as particular cases of the multiscale stabilization framework considered. Using a product formula algorithm for the solution of the coupled thermomechanical problem, the resulting algebraic system of equations has been solved using a staggered procedure in which a mechanical problem, defined by the linear momentum balance equation, under quasi-static conditions, and the incompressibility equation, is solved first at constant temperature. Then a thermal problem, defined by the energy balance equation, is solved keeping constant the mechanical variables, i.e. velocity and pressure. The computational model has been implemented in an enhanced version of the finite element software COMET, developed by the authors at the International Center for Numerical Methods in Engineering (CIMNE). Two numerical examples have been considered. The first one deals with the numerical simulation of a coupled thermomechanical flow in a 2D rectangular domain. Steady-state and transient conditions have been considered. The goal of this numerical example has been the comparison between different sub-grid scale stabilization methods for the velocity and temperature equations. In particular, using a GLS stabilization method for the pressure equation, a comparison between SUPG and OSGS convective stabilization methods has been performed. Additionally, using a SUPG stabilization method for the temperature equation, a comparison between GLS and OSGS pressure stabilization methods has been done. The second example deals with the 3D numerical simulation of a representative FSW process. Numerical results obtained have been compared with experimental results available in the literature. A good agreement on the temperature distribution has been obtained and predicted peak temperatures compare well, both in value and position, with the experimental results available.
Abstract
This paper deals with the computational modeling and sub-grid scale stabilization of incompressibility and convection in the numerical simulation of the material flow around [...]
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Comparison of a Fluid and a Solid Approach for the Numerical Simulation of Friction Stir Welding with a Non‐Cylindrical Pin
P. Bussetta, N. Dialami, R. Boman, M. Chiumenti, C. Agelet de Saracibar, M. Cervera, J. Ponthot

Steel Research International (2014). (preprint) Vol. 85 (6), pp. 968-979

Abstract
Friction stir welding (FSW) process is a solid‐state joining process during which materials to be joined are not melted. As a consequence, the heat‐affected zone is smaller and the quality of the weld is better with respect to more classical welding processes. Because of extremely high strains in the neighborhood of the tool, classical numerical simulation techniques have to be extended in order to track the correct material deformations. The Arbitrary Lagrangian–Eulerian (ALE) formulation is used to preserve a good mesh quality throughout the computation. With this formulation, the mesh displacement is independent from the material displacement. Moreover, some advanced numerical techniques such as remeshing or a special computation of transition interface is needed to take into account non‐cylindrical tools. During the FSW process, the behavior of the material in the neighborhood of the tool is at the interface between solid mechanics and fluid mechanics. Consequently, a numerical model of the FSW process based on a solid formulation is compared to another one based on a fluid formulation. It is shown that these two formulations essentially deliver the same results in terms of pressures and temperatures.
Abstract
Friction stir welding (FSW) process is a solid‐state joining process during which materials to be joined are not melted. As a consequence, the heat‐affected zone is smaller [...]
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Identificaçao modal estocástica de estruturas de engengharia civil
F. Magalhaes, A. Cunha, E. Caetano

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2005). MIS54, ISBN: 84-95999-77-3

Abstract
Neste contexto, as técnicas de identificaçao dos parámetros modais da estrutura (frequencias naturais, configuraçoes dos modos de vibraçao e coeficientes de amortecimento modais) com base na realizaçao de ensaios dinámicos surgem com ferramentas de grande interesse, no sentido de dar suporte à análise de correlaçao entre parámetros identificados e calculados, à actualizaçao e validaçao experimental das modelaçoes numéricas desenvolvidas e subsequente avalidaçao experimental das modelaçoes numéricad desenvolvidas e subsequente avaliaçao da capacidade de carga efectiva das estruturas.
Abstract
Neste contexto, as técnicas de identificaçao dos parámetros modais da estrutura (frequencias naturais, configuraçoes dos modos de vibraçao [...]
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Ferrocemento: Un acercamiento al diseño sísmico
D. Bedoya, J. Farbiaz, J. Hurtado, L. Pujades

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2002). MIS50, ISBN: 84--95999-23-4

Abstract
El estudio que aquí se expone propone una alternativa al diseño y construcción de viviendas de interés social, ubicadas en zonas de alta sismicidad, utilizando como material de construcción el ferrocemento. En Colombia, y bajo la jurisdicción de las Normas Colombianas de Diseño y Construcción Sismo Resistentes, NSR-98 (Ley 400 de 1997, y sus decretos reglamentarios), la vivienda de bajo costo se construye generalmente con mampostería estructural, respaldada por el Título D, Mampostería Estructural, o por el Título E, Casas de uno y dos pisos, que desde febrero de 2002 incluye construcciones en mampostería confinada y construcciones en bahareque encementado.
Abstract
El estudio que aquí se expone propone una alternativa al diseño y construcción de viviendas de interés social, ubicadas en zonas de alta sismicidad, [...]
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Criterio de diseño de puentes con aisladores y disipadores de energía
M. Jara, J. Casas

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2002). MIS49, ISBN: 84-95999-02-1

Abstract
La búsqueda de medios para proporcionar suficiente resistencia a una estructura y asegurar un comportamiento satisfactorio para diferentes niveles de intensidad sísmica, ha proporcionado un desarrollo notable en los últimos veinte años del uso de los sistemas de control de vibraciones. El concepto general en el que se basan estos dispositivos consiste en el aumento de la capacidad del sistema para disipar energía, mediante la aplicación de fuerzas pasivas o activas, contrarias a las generadas por la acción externa. También se reconoce la importancia de controlar el periodo de la estructura para evitar que coincida con las frecuencias en las que se concentra la mayor parte de la energía del sismo. A la fecha los sistemas de control pasivo son los que han sido empleados con mayor frecuencia, y entre ellos, el aislamiento de base el más utilizado. Las razones por las que se ha preferido estos sistemas son de carácter económico, de fiabilidad, de mantenimiento y a su mayor desarrollo teórico y tecnológico. Los apoyos de neopreno y los apoyos deslizantes que se utilizan en el diseño de puentes para permitir los movimientos horizontales del tablero producidos por la temperatura y la reología, son un antecedente que facilita la adaptación tecnológica de los dispositivos de aislamiento de base y disipación de energía pasiva. Además de la necesidad de mantener en operación los puentes estratégicos después de la ocurrencia de un sismo destructivo, las características estructurales de estos sistemas y su alta vulnerabilidad sísmica, los hacen candidatos idóneos para el uso de dispositivos de control para su protección frente a sismo.
Abstract
La búsqueda de medios para proporcionar suficiente resistencia a una estructura y asegurar un comportamiento satisfactorio para diferentes niveles de intensidad sísmica, [...]
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Control de vibraciones en puentes. Un estado del arte y de la práctica
A. Jarauta, J. Casas

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2002). MIS48, ISBN: 84-95999-01-3

Abstract
Los daños que producen los sismos en los sistemas de transporte, suelen tener un impacto significativo en el total de las pérdidas económicas producidas por estos eventos, tanto por los gastos que provienen directamente de la rehabilitación y sustitución de las estructuras dañadas, como por los costos indirectos debidos al cierre temporal de las vías de comunicación, que afectan los tiempos de desplazamiento en las rutas comerciales durante periodos que pueden prolongarse durante varios meses. En algunos casos, la pérdida de vidas humanas se ha incrementado de forma importante como consecuencia directa del derrumbe de algunos puentes; además, debe considerarse que la interrupción del tránsito, puede obstacularizar las labores de rescate, así como el transporte de víveres, medicinas y materiales, a las zonas afectadas. La actividad sísmica de las últimas décadas ha puesto de manifiesto la vulnerabilidad de los puentes ante este fenómeno, y ha dejado constancia de los grandes costos derivados de los fallos que se producen en los mismos. Sismos como el de San Fernando (1971), Tangshan (1976), Loma Prieta (1989), Northridge (1994), Kobe (1995) y Taiwan (1999), entre otros, han provocado fallos de importancia en los sistemas de transporte, y han incrementado las pérdidas económicas de forma notable. En la siguiente sección, presentamos un panorama general de la magnitud del problema, mediante una breve descripción de las consecuencias derivadas de los daños provocados en los puentes, por algunos de los sismos más importantes ocurridos en el mundo en los últimos años.
Abstract
Los daños que producen los sismos en los sistemas de transporte, suelen tener un impacto significativo en el total de las pérdidas económicas producidas [...]
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Estudio analítico sobre el comportamiento sísmico de muros de mampostería confinada con aberturas
J. Alvarez, S. Alcocer

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2001). MIS46, ISBN: 84-89925-90-9

Abstract
El objetivo fundamental de este trabajo, es estudiar de manera analítica las implicaciones que tiene la existencia de aberturas en la degradación de resistencia y de rigidez en muros de mampostería confinadas. Se han elaborado y analizado varios modelos no lineales de elementos finitos de muros de mampostería confinada con y sin aberturas.
Abstract
El objetivo fundamental de este trabajo, es estudiar de manera analítica las implicaciones que tiene la existencia de aberturas en la degradación de resistencia [...]
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Evaluación del daño en edificios y desempeño sísmico programa de ordenador CEINCI3
R. Aguiar

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2001). MIS45, ISBN: 84-89925-87-9

Abstract
Las normas que están vigentes en la mayoría de los códigos y normativas sísmicas tienen un objetivo principal: que la estructura tenga un buen comportamiento inelástico ante un sismo severo, el mismo que se define mediante estudios de peligrosidad sísmica, considerando una vida útil de la estructura de 50 años y con un 10% de probabilidad de excedencia. Este mismo tiene un período de retorno que está alrededor de los 475 años. Para este evento, que tiene muy poca probabilidad de registrarse durante la vida útil de la estructura, se desea, que la edificación disipe la mayor cantidad de energía y no colapse. De tal forma que el objetivo principal de la mayor parte de los códigos es salvar vidas para el sismo severo El objetivo indicado en el párrafo anterior, se ha venido cumpliendo en la práctica, en estructuras bien diseñadas pero cuando se han registrado sismos de menor magnitud, con aceleraciones menores a las esperadas en el sismo severo se ha visto que el daño estructural y no estructural es demasiado grande de tal manera que las pérdidas registradas han sido cuantiosas, inaceptables para la sociedad y sus gobiernos. Esto se lo ha comprobado en distintos países como México, USA, entre otros.
Abstract
Las normas que están vigentes en la mayoría de los códigos y normativas sísmicas tienen un objetivo principal: que la estructura tenga un buen [...]
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An apropos kinematic framework for the numerical modelling of Friction Stir Welding
N. Dialami, M. Chiumenti, M. Cervera, C. Agelet de Saracibar

Computers and Structures (2013). (prepint) Vol. 117, pp. 48-57.

Abstract
This paper describes features of a fully coupled thermo-mechanical model for Friction Stir Welding (FSW) simulation. An apropos kinematic setting for different zones of the computational domain is introduced and an efficient coupling strategy is proposed. Heat generation via viscous dissipation as well as frictional heating is considered. The results of the simulation using the proposed model are compared with the experimental evidence. The effect of slip and stick condition on non-circular pin shapes is analyzed. Simulation of material stirring is also carried out via particle tracing, providing insight of the material flow pattern in the vicinity of the pin.
Abstract
This paper describes features of a fully coupled thermo-mechanical model for Friction Stir Welding (FSW) simulation. An apropos kinematic setting for different zones of the [...]
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Capacidad límite última de disipación de energía de estructuras de hormigón armado sometidas a acciones sísmicas
A. Benavent-Climent, F. López-Almansa, L. Pujades

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2001). MIS44, ISBN: 84-899925-88-7

Abstract
El principal objetivo de esta monografía es la evaluación de la capacidad límite de disipación de energía de las estructuras sometidas a terremotos. En ella se expone, a través de su aplicación a varias estructuras tipo, una de las metodologías posibles para llevarla a cabo.
Abstract
El principal objetivo de esta monografía es la evaluación de la capacidad límite de disipación de energía de las estructuras sometidas a [...]
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Espectros de input de energía de aplicación en el proyecto sismorresistente de estructuras en regiones de sismicidad moderada
A. Benavent-Climent, L. Pujades, F. López-Almansa

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2001). MIS43, ISBN: 84-89925-86-0

Abstract
Esta monografía se compone de seis capítulos. En el Capítulo 1 se introduce el concepto de la energía y se demuestra la dependencia que tiene el input de energía total, del periodo fundamental de vvibración y de la masa del edificio. En el capítulo 2 se hace una estimación indirecta de los espectros de input de energía implícitos en la normativa sísmica española vigente (CSE-94), a partir de la hipóyesis de Housner y de las relaciones conocidas entre la pseudo-velocidad máximarelativa y la aceleración máxima absoluta de respuesta en sistemas dinámicos de un grado de libertad. En el Capítulo 3 se determinan mediante cálculos dinámicos directos, los espectros de input de energía de más de 100 acelerogramas correspondientes a terremotos históricos registrados en España. El Capítulo 4 se dedica a la evolución del input de energía que contribuye a daños estructurales, a partir del input de energía total y se expone nuevas fórmulas propuestas recientemente en la literatura. Finalmente, los Capítulos 5 y 6 se ocupan de comparar los espectros de input de energía de proyecto propuestos en diversas áreas geográficas de diferente sismicidad. Estos espectros de proyecto se contrastan también con los correspondientes a los recientes de Turquía, Taiwán y Mula de 1999.
Abstract
Esta monografía se compone de seis capítulos. En el Capítulo 1 se introduce el concepto de la energía y se demuestra la dependencia que tiene el [...]
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Continuum FE models for the analysis of a representative bay in Mallorca Cathedral
P. Roca, M. Cervera, L. Pelà

Engineering Structures (2013). (preprint) Vol. 46, pp. 653-670

Abstract
From the theoretical point of view, systems composed by masonry arches or vaults would require, during construction, the simultaneous activation of all structural elements in order to reach the optimum balance of thrusts. This is not obviously the case of complex ancient masonry constructions, whose long and gradual building process may have contributed to their deformed condition and even to damage.In this paper, the possible influence of the construction process as well as that of later long-term deformation on the final condition of the building is investigated in the case of a complex and large historical structure, namely Mallorca Cathedral. A FE code has been specifically developed for the present study. The code is able to account for construction processes through sequential-evolutionary analyses, with the description of masonry mechanical damage and long-term deformation. The representative bay of the cathedral is analyzed taking into account different construction phases, as emerged from historical research. The response of such substructure to transverse earthquake equivalent forces is then investigated. In this case, the damage model is improved with a local crack-tracking algorithm. This numerical strategy models the tensile damage as distinct cracks, leading to a better prediction of realistic collapsing mechanisms.
Abstract
From the theoretical point of view, systems composed by masonry arches or vaults would require, during construction, the simultaneous activation of all structural elements [...]
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An orthotropic damage model for the analysis of masonry structures
L. Pelà, M. Cervera, P. Roca

Construction and Building Materials (2013). (preprint) Vol. 41, pp. 957-967.

Abstract
This paper presents a numerical model for nonlinear analysis of masonry structural elements based on Continuum Damage Mechanics. The material is described at the macro-level, i.e. it is modeled as a homogeneous orthotropic continuum. The orthotropic behavior is simulated by means of an original methodology, resulting from the concept of mapped tensors from the anisotropic field to an auxiliary workspace. The application of this idea to strain-based Continuum Damage Models is innovative and leads to several computational benefits. The suitability of the model for representing the behavior of different types of brickwork masonry is shown via the simulation of experimental tests.
Abstract
This paper presents a numerical model for nonlinear analysis of masonry structural elements based on Continuum Damage Mechanics. The material is described at the macro-level, [...]
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Viscoelasticity and damage model for creep behaviour of historical masonry structures
P. Roca, M. Cervera, L. Pelà, R. Clemente, M. Chiumenti

The Open Civil Engineering Journal (2012). Vol. 6 (Suppl. 1-M7), pp. 188-199.

Abstract
This paper presents a continuum model for the simulation of the viscous effects and the long-term damage accumulation in masonry structures. The rheological model is based on a generalized Maxwell chain representation with a constitutive law utilizing a limited number of internal variables. Thanks to its computational efficiency, this approach is suitable for the analysis of large and complex structures. In the paper, the viscous and damage models are presented and their coupling is discussed. The FE simulation of the construction process of the representative bay of Mallorca Cathedral is presented, together with the analysis of the long-term effects. The parameters of the model are tentatively calibrated on the basis of the time-dependent viscous deformations detected during the cathedral monitoring.
Abstract
This paper presents a continuum model for the simulation of the viscous effects and the long-term damage accumulation in masonry structures. The rheological model is based [...]
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Structural Analysis of Masonry Historical Constructions. Classical and Advanced Approaches
P. Roca, M. Cervera, G. Gariup, L. Pelà

Archives of Comp. Meths. Engng. (2010). 17 (3), pp. 299-325

Abstract
A review of methods applicable to the study of masonry historical construction, encompassing both classical and advanced ones, is presented. Firstly, the paper offers a discussion on the main challenges posed by historical structures and the desirable conditions that approaches oriented to the modeling and analysis of this type of structures should accomplish. Secondly, the main available methods which are actually used for study masonry historical structures are referred to and discussed. The main available strategies, including limit analysis, simplified methods, FEM macro- or micro-modeling and discrete element methods (DEM) are considered with regard to their realism, computer efficiency, data availability and real applicability to large structures. A set of final considerations are offered on the real possibility of carrying out realistic analysis of complex historic masonry structures. In spite of the modern developments, the study of historical buildings is still facing significant difficulties linked to computational effort, possibility of input data acquisition and limited realism of methods.
Abstract
A review of methods applicable to the study of masonry historical construction, encompassing both classical and advanced ones, is presented. Firstly, the paper offers a discussion [...]
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A crack-tracking technique for localized damage in quasi-brittle materials
M. Cervera, L. Pelà, R. Clemente, P. Roca

Engineering Fracture Mechanics (2010). Vol. 77 (13), pp. 2431-2450.

Abstract
This work presents a procedure to simulate the growth and propagation of localized tensile cracks on quasi-brittle materials. The so-called smeared damage approach, which consists in standard finite elements and local nonlinear constitutive laws, is recovered and improved in order to represent crack localization and avoid spurious mesh-bias dependence in the discrete problem. This is achieved by means of the implementation of a local crack-tracking algorithm which can reproduce individual (discrete) cracks and ensure objectivity of the finite element problem solution. The performance of the localized damage model is stressed by means of the analyses of structural case-studies. Compared to the Smeared Crack Approach in its original form, the presented procedure shows clearly a better capacity to predict realistic collapse mechanisms. The proposed tracking technique is relatively inexpensive.
Abstract
This work presents a procedure to simulate the growth and propagation of localized tensile cracks on quasi-brittle materials. The so-called smeared damage approach, which [...]
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Size effect and localization in J2 plasticity
M. Cervera, M. Chiumenti

Int. J. Solids and Structures (2009). Vol. 46 (17), pp. 3301-3312.

Abstract
This paper studies the phenomenon of structural size effect and strain localization in J2 plasticity. Size effect is here understood as the change in the response of a given structure when the spatial dimensions are scaled up or down while the geometry and other relevant properties of the structure are preserved. The work exploits the advantages of the mixed displacement–pressure formulation in incompressible or quasi-incompressible situations. Elasto-J2-plastic constitutive behaviour with regularized softening is considered. Stability issues are discussed to ensure existence and uniqueness of the solution of the corresponding discrete finite element formulation. Numerical examples show that the formulation derived is able to solve a wide range of structural scales, including real life engineering applications. The results obtained do not suffer from spurious mesh dependence. Furthermore, the formulation includes the classical theories of perfect plasticity and linear fracture mechanics as limit cases.
Abstract
This paper studies the phenomenon of structural size effect and strain localization in J2 plasticity. Size effect is here understood as the change in the response of a given [...]
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On the Numerical modeling of the thermomechanical contact for metal casting analysis
M. Chiumenti, C. Agelet de Saracibar, M. Cervera

J. Heat Transfer (2008). Vol. 130 (6), 10 pp.

Abstract
The paper shows the intrinsic difficulties found in the numerical simulation of industrial casting processes using finite element (FE) analysis. Up until now, uncoupled pure thermal simulations have been mostly considered to model solidification and cooling phenomena. However, a fully coupled thermomechanical analysis provides a more complete insight of the casting process and the final outcome regarding the quality of the part. In this type of analysis, the thermomechanical model used plays a role of paramount importance, as the problem is coupled both ways through contact between part and mould. The paper presents the full statement of the problem regarding contact, and it considers the difficulties associated with FE mesh generation and time integration strategy. It also reviews soft and hard algorithms for mechanical contact presenting some new alternatives. Evaluation of coefficients used for thermal contact is also discussed, and a new proposal is presented. Finally, some numerical applications are presented to assess the performance of the proposed strategies both in benchmark and industrial problems.
Abstract
The paper shows the intrinsic difficulties found in the numerical simulation of industrial casting processes using finite element (FE) analysis. Up until now, uncoupled pure [...]
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Current Developments on the Coupled Thermomechanical Computational Modeling of Metal Casting Processes
C. Agelet de Saracibar, M. Chiumenti, M. Cervera

Computer Methods in Material Science (2006). Vol. 6 (1-2), pp. 15-25

Abstract
In this paper, current developments on the coupled thermomechanical computational simulation of metal casting processes are presented A thermodynamically consistent constitutive material model is derived from a thermoviscoplastic free energy function. A continuous transition between the initial fluid-like and the final solid-like is modeled by considering a J2 thermoviscoplastic model. Thus, an thermoelastoviscoplastic model, suitable for the solid-like phase, degenerates into a pure thermoviscous model, suitable for the liquid-like phase, according to the evolution of the solid fraction function. A thermomechanical contact model, taking into account the insulated effects of the air-gap due to thermal shrinkage of the part during solidification and cooling, is introduced. A fractional step method, arising from an operator split of the governing differential equations, is considered to solve the coupled problem using a staggered scheme. Within a finite element setting, using low-order interpolation elements, a multiscale stabilization technique is introduced as a convenient framework to overcome the Babuska-Brezzi condition and avoid volumetric locking and pressure instabilities arising in incompressible or quasi-incompressible problems. Computational simulation of industrial castings show the good performance of the model.
Abstract
In this paper, current developments on the coupled thermomechanical computational simulation of metal casting processes are presented A thermodynamically consistent constitutive [...]
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Smeared crack approach: back to the original track
M. Cervera, M. Chiumenti

Int. J. Numer. Anal. Meth. Geomech. (2006). Vol. 30 (12), pp. 1173-1199.

Abstract
This paper briefly reviews the formulations used over the last 40 years for the solution of problems involving tensile cracking, with both the discrete and the smeared crack approaches. The paper focuses on the smeared approach, identifying as its main drawbacks the observed mesh‐size and mesh‐bias spurious dependence when the method is applied ‘straightly’. A simple isotropic local damage constitutive model is considered, and the (exponential) softening modulus is regularized according to the material fracture energy and the element size. The continuum and discrete mechanical problems corresponding to both the weak discontinuity (smeared cracks) and the strong discontinuity (discrete cracks) approaches are analysed and the question of propagation of the strain localization band (crack) is identified as the main difficulty to be overcome in the numerical procedure. A tracking technique is used to ensure stability of the solution, attaining the necessary convergence properties of the corresponding discrete finite element formulation. Numerical examples show that the formulation derived is stable and remarkably robust. As a consequence, the results obtained do not suffer from spurious mesh‐size or mesh‐bias dependence, comparing very favourably with those obtained with other fracture and continuum mechanics approaches.
Abstract
This paper briefly reviews the formulations used over the last 40 years for the solution of problems involving tensile cracking, with both the discrete and the smeared crack [...]
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Fuerzas sísmicas en lo países bolivarianos
R. Aguiar

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2000). MIS42, ISBN: 84-89925-74-7

Abstract
Se muestran las normativas en Venezuela, Colombia , Ecuador y Perú, en lo referente a las acciones sísmicas de diseño.
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Modelos de vulnerabilidad sísmica de puentes basado en "conjuntos difusos"
E. Maldonado, J. Casas, J. Canas

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2000). MIS40, ISBN: 84-84-89925-62-3

Abstract
En este trabajo se presenta un modelo rápido y sencillo de evaluación de la vulnerabilidad sísmica de puentes a escala regional. El modelo fue estructurado de forma que puede ser aplicado especialmente a zonas donde no se cuenta con reportes de daños sísmicos de puentes. El método se basa en la identificación de las características más relevantes e influyentes en el daño que sufrirá un puente bajo la acción del sismo. La valoración de estas características fue realizada mediante la determinación de diecinueve (19) parámetros, a los cuales se les asignó un grado de vulnerabilidad y un valor de importancia en base a la opinión de expertos. Debido a las impresiciones y subjetividad de las opiniones, estas fueron procesadas mediante técnicas difusas. Una vez calificados cada uno de los parámetros, se procedió a relacionar las calificaciones de los parámetros con su valor de importancia por medio de un promedio ponderando difuso. El resultado de esta relación por medio de técnicas basadas en la lógica difusa corresponde al “índice de vulnerabilidad del puente”.
Abstract
En este trabajo se presenta un modelo rápido y sencillo de evaluación de la vulnerabilidad sísmica de puentes a escala regional. El modelo fue estructurado [...]
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Utilización de los conjuntos difusos en modelos de vulnerabilidad sísmica
E. Maldonado, J. Casas, J. Canas

Monograph Series in Earthquake Engineering (CIMNE) (2019). 26

Abstract
En este trabajo de presentan las bases teóricas de los conjuntos difusos necesarias para desarrollar un modelo de vulnerabilidad sísmica basado en opinión de expertos. Para ello, en una primera parte, se estudian los conceptos fundamentales como la definición de conjunto difuso, el concepto de función de pertenencia, el concepto de variable lingüística y las operaciones aritméticas. En la segunda parte, se presentan ejemplos de modelos de vulnerabilidad sísmica desarrollados en base a opinión de expertos, siendo el primero de ellos un claro ejemplo de la utilización de la teoría difusa para el tratamiento de las opiniones.
Abstract
En este trabajo de presentan las bases teóricas de los conjuntos difusos necesarias para desarrollar un modelo de vulnerabilidad sísmica basado en opinión [...]
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Dinámica de estructuras. Aplicaciones a la ingeniería sísmica
J. Hurtado

Monograph Series in Earthquake Engineering, editor A. H. Barbat (2000). MIS38, ISBN: 84-89925-59-3

Abstract
El presente trabajo está concebido solamente como una introducción al tema que no obstante reúne de manera directa y suficiente los conocimientos requeridos en la práctica usual del diseño de edificaciones, en especial para el caso sísmico. Se han incluido varios programas de cálculo escritos en lenguaje MATLAB, los cuales son utilizados para la solución del ejemplo
Abstract
El presente trabajo está concebido solamente como una introducción al tema que no obstante reúne de manera directa y suficiente los conocimientos [...]
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Estimación de efectos locales con movimientos sísmicos y microtemblores
V. Giraldo, A. Alfaro, L. Pujades, J. Canas

Monograph Series in Earthquake Engineering (CIMNE) (2019). 24

Abstract
Se presenta una visión amplia de la utilización de registros de movimiento sísmicos fuertes, movimientos sísmicos débiles y microtemblores para la evaluación de efectos locales. La revisión del estado del arte enfatiza en el análisis de microtemblores debido a la facilidad de la obtención de los registros en cualquier sitio.
Abstract
Se presenta una visión amplia de la utilización de registros de movimiento sísmicos fuertes, movimientos sísmicos débiles y microtemblores [...]
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Plasticidad y fractura en estructuras aporticadas
J. Flórez-López

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1999). MIS35, ISBN: 84-89925-46-1

Abstract
En esta monografía se presenta una teoría general de pórticos planos, que incluye desde el modelo elástico lineal tradicional hasta una mecánica de la fractura para estructuras aporticadas. A diferencia de los textos tradicionales de la teoría de estructuras, se hace énfasis en los aspectos no lineales e inelásticos del problema, específicamente en el problema del daño y fractura en estructuras aporticadas.
Abstract
En esta monografía se presenta una teoría general de pórticos planos, que incluye desde el modelo elástico lineal tradicional hasta una mecánica [...]
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Earthquake simulator testing of a steel model seismically protected with friction energy dissipators
D. Foti, J. Canas

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1999). MIS34, ISBN: 84-89925-40-2

Abstract
In this research the study of an experimental reduced scale stell model of a medium-rise building structure is presented. The model was dynamically protected with energy dissipators installed on rigidization diagonals. These devices are passive control elements able to reduce the earthquake forces in buildings. The energy dissipators utilized in the experimental tests principally involve the steel-steel friction to dissipate energy and to lower the seismic response. When the structure undergoes interstory drifts the devices dissipate energy increasing the damping of the structure.
Abstract
In this research the study of an experimental reduced scale stell model of a medium-rise building structure is presented. The model was dynamically protected with energy dissipators [...]
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Modelación estocástica de la acción sísmica
J. Hurtado

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1999). MIS33, ISBN: 84-89925-34-8

Abstract
En este trabajo se desarrolla la estimación de un modelo estocástico de la variación temporal de las ondas sísmicas para la ciudad de Manizales (Colombia) con base en los registros obtenidos allí en años recientes
Abstract
En este trabajo se desarrolla la estimación de un modelo estocástico de la variación temporal de las ondas sísmicas para la ciudad de Manizales [...]
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Modeling material failure in concrete structures under cyclic actions
R. Faria, M. Cervera, J. Oliver

Journal of Structural Engineering (2004). 130 (12), pp. 1997-2005.

Abstract
A constitutive model devised for the analysis of concrete structures, and suitable for generic two- or three-dimensional applications, is presented and validated. For plain concrete a tension-compression distinguishing stress split is performed, and two scalar damage variables account for the degradation induced by the tensile and compressive stress components. As outcomes the model reproduces the stiffness recovery upon load reversal, and it captures the strength enhancement under multiaxial compression. Besides, the simple formulation as well as the extremely reduced number of parameters involved in the concrete model makes it quite suitable for the analysis of real structures, and constitutes a useful design tool. As regards to the nonlinear performance of the steel reinforcement, the explicit Giuffrè–Menegotto–Pinto model is adopted. Efficiency of the global model is illustrated via two seismic applications: one concerning an arch dam, and the other a six-floor reinforced concrete wall. The latter application is presented for validation purposes.
Abstract
A constitutive model devised for the analysis of concrete structures, and suitable for generic two- or three-dimensional applications, is presented and validated. For plain [...]
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Vulnerabilidad sísmica de hospitales. Fundamentos para ingenieros y arquitectos
O. Cardona

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1999). MIS32, ISBN: 84-89925-33-X

Abstract
El propósito de esta monografía es informar a las personas involucradas en la planeación, operación, manejo y diseño de servicios de salud a cerca de los efectos que pueden sufrir los hospitales por la ocurrencia de movimientos sísmicos, con el fin de suministrar una herramienta útil que les permita incorporar los procedimientos de mitigación del riesgo, tanto en la inspección de las instalaciones existentes como en el diseño y construcción de nuevas edificaciones y servicios. El documento trata temas específicos relacionados con los problemas potenciales que se pueden generar en el caso de la ocurrencia de un sísmo e, igualmente, hace referencia a las medidas que se deben tomar para la mitigación, haciendo especial énfasis en los requisitos necesarios para que las instalaciones puedan mantener su función durante e inmediatamente después de un evento intenso. No obstante que las instalaciones de la salud pueden ser afectadas por un amplio espectro de fenómenos naturales como sismos, huracanes, deslizamientos, erupciones volcánicas, inundaciones, etc., o de origen antrópico, como incendios, explosiones, escapes de gas, entre otros, este documento hace énfasis en el problema sísmico, dado que es el fenómeno natural que más ha afectado las instalaciones de la salud y debido a que si se logra reducir sus efectos directos e indirectos, prácticamente se está reduciendo el riesgo que pueden causar otros fenómenos, cuya acción es normalmente menos que la de los sismos.
Abstract
El propósito de esta monografía es informar a las personas involucradas en la planeación, operación, manejo y diseño de servicios de salud [...]
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A stabilized formulation for incompressible plasticity using linear triangles and tetrahedra
M. Chiumenti, Q. Valverde, C. Agelet de Saracibar, M. Cervera

International Journal of Plasticity (2004). 20 (8-9), pp. 1487-1504

Abstract
In this paper, a stabilized finite element method to deal with incompressibility in solid mechanics is presented. Both elastic and J2-plastic constitutive behavior have been considered. A mixed formulation involving pressure and displacement fields is used and a continuous linear interpolation is considered for both fields. To circumvent the Babuška–Brezzi condition a stabilization technique based on the orthogonal sub-scale method is introduced. The main advantage of the method is the possibility of using linear triangular or tetrahedral finite elements, which are easy to generate for real industrial applications. Results are compared with standard Galerkin and Q1P0 mixed formulations in either elastic or elasto-plastic incompressible problems.
Abstract
In this paper, a stabilized finite element method to deal with incompressibility in solid mechanics is presented. Both elastic and J2-plastic constitutive behavior have been [...]
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Softening, localization and stabilization: capture of discontinuous solutions in J2 plasticity
M. Cervera, M. Chiumenti, C. Agelet de Saracibar

Int. J. Numer. Anal. Meth. Geomech. (2004). 28 (5), pp. 373-393.

Abstract
This paper exploits the concept of stabilization techniques to improve the behaviour of mixed linear/linear simplicial elements (triangles and tetrahedra) in incompressible or nearly incompressible situations. Elasto‐J2‐plastic constitutive behaviour has been considered with linear and exponential softening. Two different stabilization methods are used to attain global stability of the corresponding discrete finite element formulation. Implementation and computational aspects are also discussed, showing that a robust application of the proposed formulation is feasible. Numerical examples show that the formulation derived is free of volumetric locking and spurious oscillations of the pressure. The results obtained do not suffer from spurious mesh‐size or mesh‐bias dependence, comparing very favourably with those obtained with the standard, non‐stabilized, approaches.
Abstract
This paper exploits the concept of stabilization techniques to improve the behaviour of mixed linear/linear simplicial elements (triangles and tetrahedra) in incompressible [...]
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Avaliação do comportamento sísmico de barragens de betão
R. Faria

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1998). MIS31, ISBN: 84-89925-28-3

Abstract
This monograph is devoted to the numerical evaluation of the seismic performance of concrete dams, with a particular emphasis on arch typology, here represented by the portuguese Alto Lindoso and Foz Côa dams. Koyna gravity dam, located in Indica, is also studied.
Abstract
This monograph is devoted to the numerical evaluation of the seismic performance of concrete dams, with a particular emphasis on arch typology, here represented by the portuguese [...]
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Numerical modelling of concrete curing, regarding hydration and temperature phenomena
M. Cervera, R. Faria, T. Prato, J. Oliver

Computers and Structures (2002). Vol. 80 (18–19), pp. 1511-1521

Abstract
A numerical model that accounts for the hydration and aging phenomena during the early ages of concrete curing is presented in a format suitable for a finite element implementation. Assuming the percolation of water through the hydrates already formed as the dominant mechanism of cement hydration, the model adopts an internal variable called hydration degree, whose evolution law is easily calibrated and allows an accurate prediction of the hydration heat production. Compressive strength evolution is related to the aging degree, a concept that accounts for the influences of the hydration and curing temperature on the final mechanical properties of concrete. The model capabilities are illustrated by means of a wide set of experimental tests involving ordinary and high performance concretes, and through the simulation of the concrete curing on a viaduct deck of the Öresund Link.
Abstract
A numerical model that accounts for the hydration and aging phenomena during the early ages of concrete curing is presented in a format suitable for a finite element implementation. [...]
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Acciones para el diseño sísmico de estructuras
R. Aguiar

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1998). MIS30, ISBN: 84-89925-27-5

Abstract
Se presenta la metodología de cálculo para evaluar la peligrosidad sísmica a nivel regional orientada al diseño sísmico de estructuras. Las diferentes etapas de evaluación se describen en forma crítica con la presentación de resultados encontrados en diferentes zonas del mundo.
Abstract
Se presenta la metodología de cálculo para evaluar la peligrosidad sísmica a nivel regional orientada al diseño sísmico de estructuras. [...]
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On the constitutive modeling of coupled thermomechanical phase-change problems
C. Agelet de Saracibar, M. Cervera, M. Chiumenti

International Journal of Plasticity (2001). 17 (12), pp. 1565-1622.

Abstract
This paper deals with a thermodynamically consistent numerical formulation for coupled thermoplastic problems including phase-change phenomena and frictional contact. The final goal is to get an accurate, efficient and robust numerical model, able for the numerical simulation of industrial solidification processes. Some of the current issues addressed in the paper are the following. A fractional step method arising from an operator split of the governing differential equations has been used to solve the nonlinear coupled system of equations, leading to a staggered product formula solution algorithm. Nonlinear stability issues are discussed and isentropic and isothermal operator splits are formulated. Within the isentropic split, a strong operator split design constraint is introduced, by requiring that the elastic and plastic entropy, as well as the phase-change induced elastic entropy due to the latent heat, remain fixed in the mechanical problem. The formulation of the model has been consistently derived within a thermodynamic framework. All the material properties have been considered to be temperature dependent. The constitutive behavior has been defined by a thermoviscous/elastoplastic free energy function, including a thermal multiphase change contribution. Plastic response has been modeled by a J2 temperature dependent model, including plastic hardening and thermal softening. The constitutive model proposed accounts for a continuous transition between the initial liquid state, the intermediate mushy state and the final solid state taking place in a solidification process. In particular, a pure viscous deviatoric model has been used at the initial fluid-like state. A thermomecanical contact model, including a frictional hardening and temperature dependent coupled potential, is derived within a fully consistent thermodinamical theory. The numerical model has been implemented into the computational finite element code COMET developed by the authors. Numerical simulations of solidification processes show the good performance of the computational model developed.
Abstract
This paper deals with a thermodynamically consistent numerical formulation for coupled thermoplastic problems including phase-change phenomena and frictional contact. The [...]
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Simulation of Construction of RCC Dams. II: Stress and Damage
M. Cervera, T. Prato, J. Oliver

Journal of Structural Engineering (2000). 126 (9), pp. 1062-1068

Abstract
The increasing number of roller compacted concrete (RCC) dams being built around the world demands accurate methodologies for the realistic short- and long-term evaluations of the risk of thermally induced cracking in these constructions. In this work a numerical procedure for the simulation of the construction process of RCC dams is presented. It takes into account the more relevant features of the behavior of concrete at early ages, such as hydration, aging, creep, and damage. A 2D model of the Urugua-;aaı RCC Dam, built in Argentina, is used to perform the corresponding analyses. In this second part of the paper, the mechanical aspects of the simulation are presented; long-term effects are included by incorporating a creep model that naturally accounts for the aging effects, and the risk of tensile damage is also considered. The methodology determines the stress field inside the dam at any time during the construction and in the following years. Results for the reference case assess the suitability of the adopted design. This is compared to alternative studies considering different construction schedules to conclude that for these cases changes should be introduced in the dam design.
Abstract
The increasing number of roller compacted concrete (RCC) dams being built around the world demands accurate methodologies for the realistic short- and long-term evaluations [...]
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Simulation of Construction of RCC Dams. I: Temperature and Aging
M. Cervera, J. Oliver, T. Prato

Journal of Structural Engineering (2000). 126 (9), pp. 1053-1060

Abstract
The increasing number of roller compacted concrete (RCC) dams being built around the world demands accurate methodologies for the realistic short- and long-term evaluations of the risk of thermally induced cracking in these constructions. In this work a numerical procedure for the simulation of the construction process of RCC dams is presented. It takes into account the more relevant features of the behavior of concrete at early ages, such as hydration, aging, creep, and damage. A 2D model of the Urugua-í RCC Dam, built in Argentina, is used to perform the corresponding analyses. In this first part only the thermochemical aspects of the simulation of the construction process are presented. The temperature distribution and evolution inside the dam are obtained before and after the completion of the dam. The evolution of the compressive and tensile strengths and elastic moduli and their final distribution inside the dam can also be predicted. Results from 2D and simplified vertical 1D models are compared to assess the validity of the latter, and several parametric studies are carried out. The simulation and discussion of the mechanical aspects of the construction process are relegated to a companion paper that follows.
Abstract
The increasing number of roller compacted concrete (RCC) dams being built around the world demands accurate methodologies for the realistic short- and long-term evaluations [...]
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Metodologias para o cálculo sísmico não-linear de barragens de betão
R. Faria

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1998). MIS29, ISBN: 84-89925-25-9

Abstract
In this monograph the basic methodologies for the non-linear seismic analysis of concrete dams are presented. The Finite Element Method is used to discretize the dam-foundation-reservoir ensemble, whereas the dynamic equations will be solved in the time domain according to implicit integration schemes, namely the Newmark method and the Hilber-Hughes-Taylor alpha method. For the non-linear problem a predictor multicorrector algorithm is adopted. In view of the large scale computations inherent to dam analysis, a constitutive damage model for massive concrete is briefly presented. Attention is devoted to the numerical noire which arises from direct time integration, and to its control through the algorithmic dissipation provied by the alpha method, or by a s stiffness proportional damping matrix which is updated to account for material degradation. Special care is devoted to the simulation of the reservoir. Numerical modelling of the hydrodynamic effect is discussed in detail, either by means of pressure or displacement formulations, or even through the technique of the added masses form Westergaard.
Abstract
In this monograph the basic methodologies for the non-linear seismic analysis of concrete dams are presented. The Finite Element Method is used to discretize the dam-foundation-reservoir [...]
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Estudio de parámetros en la vulnerabilidad sísmica de puentes
E. Maldonado, J. Canas, J. Casas

Monograph Series in Earthquake Engineering (CIMNE) (2019). 16

Abstract
Como una primera aproximación al desarrollo del análisis de vulnerabilidad sísmica de puentes, hemos llevado a cabo el presente estudio del estado del arte acerca de este tema. El objetivo final fue tener un resumen de las metodolosgías existentes, tal que ellas permitan ofrecer las bases para el planteamiento de una metodología de evaluación de vulnerabilidad sísmica en zonas donde no hay registros de daños sísmicos de puentes.
Abstract
Como una primera aproximación al desarrollo del análisis de vulnerabilidad sísmica de puentes, hemos llevado a cabo el presente estudio del estado del [...]
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Respuesta de puentes frente a acciones sísmicas
E. Maldonado, J. Canas, J. Casas, L. Pujades

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1998). MIS27, ISBN: 84-89925-23-2

Abstract
Este trabajo tiene como objetivo el estudiar los aspectos más importantes involucrados en la respuesta de un puente ante la acción sísmica. Se presentan aspectos como la modelación del puente ante la acción sísmica, la determinación de las características dinámicas, la modelación de la acción del sismo y las metodologías de análisis. Todo lo anterior sin olvidar lo aprendido de los daños registrados en los puentes ante sismos pasados. Finalmente, esta monografía busca logar un entendimiento mínimo y necesario del comportamiento de un puente ante la acción del sismo, para que de esta manera se cuente con una herramienta útil para definir los parámetros que influyen en la vulnerabilidad sísmica de los puentes.
Abstract
Este trabajo tiene como objetivo el estudiar los aspectos más importantes involucrados en la respuesta de un puente ante la acción sísmica. Se presentan [...]
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Análisis de los acelerogramas de la Serie de Adra (Almería). Diciembre 1993 a enero 1994
R. Blázquez, A. Suárez, E. Carreño, A. Martín

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1998). MIS26, ISBN: 84-89925-11-9

Abstract
Se analizan en este trabajo los datos acelerográficos asociados a los dos sismos principlaes de la denomianda serie de Adra. El estudio realizado se centra en la caracterización ingenieril de los acelerogramas correspondientes a los dos sismos principales de la Serie de Adra, tanto en el dominio temporal (historias de aceleraciones, velocidades y desplazamientos), como el frecuencial (espectros de respuesta).
Abstract
Se analizan en este trabajo los datos acelerográficos asociados a los dos sismos principlaes de la denomianda serie de Adra. El estudio realizado se centra en la caracterización [...]
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Stochastic dynamics of hysteretic structures
J. Hurtado

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1998). MIS25, ISBN: 84-89925-09

Abstract
This monographs deals with methods for analysing the random vibration of deterministic or uncertain hysteretic structures under any type of external random dynamic load. However, more attention is given to the modelling of seismic random vibration of structures.
Abstract
This monographs deals with methods for analysing the random vibration of deterministic or uncertain hysteretic structures under any type of external random dynamic load. However, [...]
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Daño sísmico global en edificios con muros de cortante
R. Aguiar

Monograph Series in Earthquake Engineering, editor A. H. Barbat (1997). MIS23, ISBN: 84-89925-00-3

Abstract
En la presente monografía se calcula el daño sísmico en edificios porticados de hormigón armado con muros de cortante, de dos formas. En la primera se obtiene el índice de daño a nivel local de los elementos y mediante una combinación ponderada del daño local se encuentra el daño global de la estructura; en este contexto de cálculo la acción sísmica viene definida por un acelerograma. En la segunda forma, se presenta una metodología para calcular el daño global sísmico, utilizando espectros de respuesta.
Abstract
En la presente monografía se calcula el daño sísmico en edificios porticados de hormigón armado con muros de cortante, de dos formas. En la primera [...]
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