Documents published in 2013 : Scipedia

Calderón faces himself: The Devotion of the Cross and The Purgatory of Saint Patrick
A. Sáez

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 22

Abstract
The Devotion of the Cross and The Purgatory of Saint Patrick are a good example of the continuous exercise of the interest that Calderón shows for auto-rewriting and use of own materials. Certainly, these two religious comedies share the turn to repentance from a sinner, the central presence of the symbol of the cross, the miracle of the soul that does not abandon the body and allows the salvation and the design of the comic agent. In short, it is a case that reveals some of the dramatic keys of the poet and his effort of perfection between different works.
Abstract
The Devotion of the Cross and The Purgatory of Saint Patrick are a good example of the continuous exercise of the interest that Calderón shows for auto-rewriting and use [...]
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Table of contents
Á. Baraibar

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 10

Abstract
Table of contents
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Lourenço, A. Apolinário y Usunáriz, Jesús M.ª, (eds.), Poderes y autoridades en el Siglo de Oro: realidad y representación, Pamplona, Eunsa, 2012, 352 pp. ISBN: 978-84-3132-889-4
A. Zúñiga Lacruz

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 4

Abstract
Book's review
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Ignacio Arellano y Carlos Mata, Vida y obra de Lope de Vega, Madrid, Homolegens (Bibliotheca Homolegens, 63), 2011, 334 pp. ISBN: 978-84-92518-72-2.
B. Belloni

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 20

Abstract
Book's review
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Álvaro Cubillo de Aragón, El invisible príncipe del Baúl, ed. Francisco Domínguez Matito, Vigo, Editorial Academia del Hispanismo, 2012, 228 pp. ISBN 978-84-15175-09-4
I. Arellano

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 21

Abstract
Book's review
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Pedro Calderón de la Barca, La vida es sueño. Edición crítica de las dos versiones del auto y de la loa de Fernando Plata Parga, Kassel/Pamplona, Edition Reichenberger/Universidad de Navarra, 2012. 287 págs. ISBN: 978-3-944244-01-3
H. Acevedo González

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 15

Abstract
Book's review
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Metrical forms, spaces and structures in ¿De cuándo acá nos vino? of Lope de Vega
M. Vitse

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 11

Abstract
The article examines the role of the metric in the structural design of the comedy ¿De cuando acá nos vino? by Lope de Vega, highlighting its importance, related, but not subordinated to the spatial changes and other criteria. The careful analysis of the metrical organization allows to note the elaborate technique of Lope, which maintains a remarkable consistency in the scenic, geographic, chronological, theatrical and metric criteria, in the step from one to another macrosequences established in the analysis.
Abstract
The article examines the role of the metric in the structural design of the comedy ¿De cuando acá nos vino? by Lope de Vega, highlighting its importance, related, but not [...]
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The Art of Conversation: A Virtuous or Inmoral Delight?
C. Strosetzki

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 3

Abstract
Recent linguistic pragmatics has emphasized that talking is acting. Action, however, belongs to the field of ethics. Hence, of what nature is the relationship that exists between the norms of ethics and the rules of conversation? The question is easy to answer on particular cases, for example, when asking about the permissibility of lying and deception. The matter, however, becomes more complex, when comparing the field of ethics to the rules of conversation, so it will be studied first. Then, the forms of regulated existence in society and conversation are correlated with those in politics and state. This raises the question of the extent to which the society that comes together in sociable conversation is to be seen in analogy to the society of state, so that parallels between the political theory and the theory of sociability can be found. Due to the special significance of Aristotle and Thomas Aquinas in the Late Scholasticism of the Spanish Golden Age, we take the Aristotelian ethics and politics as the starting point for this investigation.
Abstract
Recent linguistic pragmatics has emphasized that talking is acting. Action, however, belongs to the field of ethics. Hence, of what nature is the relationship that exists [...]
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Marmosets, Raree shows and Pulcinelle: an Analysis and Edition of a Hitherto-Unpublished Carnival Play by Antonio de Zamora
F. Plata

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 19

Abstract
This paper is an analyisis, annotation and edition of the Mojiganga del mundinovo (‘The raree show, a carnival play’) by Antonio de Zamora. The play was performed in 1698 Madrid by the troupe of Carlos Vallejo, along with the sacramental one-act play El templo vivo de Dios (‘The living temple of God’). The hitherto unpublished text is based on the only two extant manuscripts, located in archives in Madrid. Despite the play’s title, my analysis argues that the novelty in this play is not so much the raree show, a contraption popularized four decades earlier in Golden Age theater, as the marmosets. The death of two marmosets and the ensuing desolation of their owner, Ms. Estupenda, both trigger the play and provide it with a plot. The marmosets, too, point to a changing mentality in late 17th-century society, regarding the possession among ladies of marmosets and other monkeys as pets.
Abstract
This paper is an analyisis, annotation and edition of the Mojiganga del mundinovo (‘The raree show, a carnival play’) by Antonio de Zamora. The play was performed in 1698 [...]
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Burlesque Authority and Modernity in Baroque Short Theater
A. Guijarro-Donadiós

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 13

Abstract
The purpose of this article is to study how the trends of diversion and consumption determined the comic elements of the short plays through the analysis of the comic Mayor within the urban space. I focus on several interludes where commerce and the use of new products and habits are the principal means of making fun of the rural authority figure in the emerging new society of consumers in the 17th century.
Abstract
The purpose of this article is to study how the trends of diversion and consumption determined the comic elements of the short plays through the analysis of the comic Mayor [...]
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Comicality and devotion: festive laugh in Lope de Vega’s hagiographical comedia
N. Fernández Rodríguez

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 7

Abstract
Taking into consideration Lope de Vega’s corpus of hagiographical comedia, we value how the typical comicality of arte nuevo became compatible with that pious sense which was essential to hagiographical plays. We discuss the different roles played by festive laugh in a dramatic subgenre which intended to lead the audience to devotion. The aim of this article is to deepen into the strategies through which comedias de santos contributed to a double prospect, festive and pious.
Abstract
Taking into consideration Lope de Vega’s corpus of hagiographical comedia, we value how the typical comicality of arte nuevo became compatible with that pious sense which [...]
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The Deified Courtier: Pagan Spectacles in El burlador de Sevilla
F. de Armas

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 14

Abstract
This essay looks at pagan disguises utilized in plays and courtly entertainments of the Golden Age, focusing on El burlador de Sevilla. Don Juan and all those who surround him, turn to mythology, pretending to be deities and thus reflecting the theatrical culture of the court where the nobility often assumed such pagan guises. When he metamorphoses himself into Jupiter, don Juan reminds us that this particular guise was common in most European courts of the times were courtiers and kings imagined themselves as abiding in a new Olympus. Don Juan, then, defies society, utilizing the same symbols of power that served to exalt the Habsburgs. Don Juan’s power of metamorphosis is seen most clearly in Tisbea and Isabela who both play the part of Europa to the god/bull.
Abstract
This essay looks at pagan disguises utilized in plays and courtly entertainments of the Golden Age, focusing on El burlador de Sevilla. Don Juan and all those who surround [...]
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Power relationships and conflicts between families and individuals: Lope de Vega’s Los enemigos en casa
F. Antonucci

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 8

Abstract
Los enemigos en casa is a comedy written by Lope de Vega that has been scarcely studied. The plot focuses on the enmity among two sevillian families and the serious problems it causes to a couple of lovers belonging to the rival families. The article examines how Lope dramatizes intergenerational discord, showing paternal authoritarism’s excess, and most of all, the way it states the improper idea of familiar honor that’s displayed by paternal uncles, along the same lines of the arcaical role of patruus.
Abstract
Los enemigos en casa is a comedy written by Lope de Vega that has been scarcely studied. The plot focuses on the enmity among two sevillian families and the serious problems [...]
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El niño caballero’s interlude and the burlesque rewriting of Romances of Chivalry
M. Aguilar Perdomo

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 1

Abstract
In the second half of the XVII century, Spanish romances of chivalry continued providing the theater and courtly festivities with characters, topic and motifs. Antonio de Solís y Ribadeneira’s interlude, El niño caballero, picks up a number of motifs from the heroic archetype that characterizes the knight, and he rewrites them in a burlesque tone. Also, the theatrical interlude stages a play of dances that the actors, among them, the famous «Juan Rana» present to the public. The article is accompanied by the critical edition of the text.
Abstract
In the second half of the XVII century, Spanish romances of chivalry continued providing the theater and courtly festivities with characters, topic and motifs. Antonio de [...]
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Towards the burlesque novella: Salas Barbadillo, Castillo Solórzano, and Tirso’s Los tres maridos burlados
F. Rodríguez Mansilla

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 17

Abstract
This article draws attention to a type of XVIIth century novella that has been neglected or simply studied as a derivation of other literary manifestations. My objective is to define the main characteristics of a short narrative that we can name «burlesque novella». I define it as a short story (the regular extension of the baroque novella) containing in the heart of its plot an elaborate trick with an exemplary purpose. From this perspective, the burlesque novella is a show organized by noblemen for noblemen, composed by educated writers, that incorporated ridiculous characters on stage. The burlesque novella —founded by Salas Barbadillo, and continued by Castillo Solórzano and Tirso de Molina— is a narrative genre still misunderstood and in need of further exploration. Tirso’s Los tres maridos burlados is a paradigmatic literary piece from this genre.
Abstract
This article draws attention to a type of XVIIth century novella that has been neglected or simply studied as a derivation of other literary manifestations. My objective is [...]
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The academies as a social celebration of the Baroque: Their reflection in Antonio Enriquez Gomez
M. Rodríguez Cáceres

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 5

Abstract
Academias morales de las musas (1642) by Antonio Enríquez Gómez is one of those miscellaneous works that make use of academia’s narrative artifice in order to compile poems, plays and other loose works. They are articulated upon the concurrence of several interlocutors who expound their ideas and feelings through compositions with different degrees of elaboration. In those verses, Antonio Enríquez Gómez pours his concerns about a life shaken by the persecution he suffered at the hands of the Inquisition because of his crypto-Judaism. Although he covers diverse themes, he is mainly concerned with providing moral reflections, and with the pessimist recreation of neo-stoic topics.
Abstract
Academias morales de las musas (1642) by Antonio Enríquez Gómez is one of those miscellaneous works that make use of academia’s narrative artifice in order to compile [...]
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«Being absent Carlos, / what difference do the festive voices applauding him make if he hears nothing?»: Sor Juana’s loas for King Carlos the Second’s birthday
R. Rice

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 9

Abstract
Starting in 1650, Calderón de la Barca assigned a new role to the ‘loa’, elevating it artistically to the level of the ‘auto’. In America, Sor Juana Inés de la Cruz followed the Spaniard’s example by aggrandizing the panegyric loa and including the essential elements: allegorical characters, hermetic fragments, emblematic reminiscences and a sensorial setting. These loas are pieces that adhere to certain templates to glorify power and exalt authority. These templates are constituted of compositional paradigms that structure the design, in part or as a whole, of the stylistic and argumentative architecture, as Arellano correctly asserts about the Auto Sacramental but also applicable to Sor Juana’s last half of the 17th century panegyric loas. I propose an analysis of the five loas that the nun composed for Carlos the Second’s birthday that consists in identifying and comparing the compositional paradigms, to be able to formulate a three act structure based on the functional identification of the paradigms.
Abstract
Starting in 1650, Calderón de la Barca assigned a new role to the ‘loa’, elevating it artistically to the level of the ‘auto’. In America, Sor Juana Inés de la Cruz [...]
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Sacred Celebration and Political Power: Iconography of the Austrians as Advocates of the Eucharist and the Immaculate Conception in Latin America
Á. Pascual Chenel

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 2

Abstract
In a Catholic monarchy, it is to be expected that religion played a transcendentally important role. Not just from a spiritual standpoint, however, but far beyond that, it came to be one of the basic premises of the political and dynastic identity of the Habsburgs. Based upon this, a complex theological conception of politics was constructed, and all the available means of rhetoric and persuasion in Baroque society were mobilized for propagandistic dissemination. In particular, art at the service of faith became a useful instrument as the «broadcaster» of all visually transmitted ideology. In this respect, the two pillars that supported the Pietas hispanica —distinctive signs and mystic unifying agents— carried special importance: Eucharistic and Immaculist devotion professed by the monarchs of the House of Austria. By this means, the political-confessional and propagandistic complex discourse that irradiated from the heart of the Monarchs to American territory was articulated. This article will look at some of the most significant images in relation to this theme, integrating them into the political-religious discourse of the time.
Abstract
In a Catholic monarchy, it is to be expected that religion played a transcendentally important role. Not just from a spiritual standpoint, however, but far beyond that, it [...]
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Aspects of authority and power illustrated by the Portuguese canonization celebrations of Ignatius of Loyola and of Francis Javier Cristina Osswald Universidade Nova de Lisboa
C. Osswald

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 18

Abstract
The canonization of the founder of a Catholic religious order constitutes a milestone in the affirmation of authority by that order. As concerns to the Society of Jesus, it was a double canonization. Such an uncommon fact as this, clearly both demonstrates the power the Society had at the time at the Curia, and explains its intention of celebrating the auto-glorification. Its scenography, thus, aimed more to praise the triumph of the Society of Jesus through the use of allegorical figures such as Religion, Fame, Honour or Pomp, than anything else. The iconography of such festivities framed the first Jesuits saints within the history of the Society. Thus, the Portuguese jesuits paid homage, by means of the staging, to the beatified ones, the first jesuits and the martyrs. Moreover, the set pointed out its main devotions, characteristics and activities such as missionary work and teaching activities. Often canonizations of a certain figure were intimately related to political power in Early Modern Time. Therefore, Portuguese Jesuit festivities exalted, with a great vigour, feelings of nationalism during the Iberian Union’s time. In order to transmit the various aims, the organizers did not hesitate to use all Baroque celebrative resources (poetry, theatre, dance, music and visual arts). In other words, particularly luxurious and grandiose celebrations, including light, sound, colour, and odour spectacles or events (reference be made to the vases with perfume inside the churches) took place by that time.
Abstract
The canonization of the founder of a Catholic religious order constitutes a milestone in the affirmation of authority by that order. As concerns to the Society of Jesus, it [...]
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Cuevas ludens. Rhetorical and graphic games in Homage to Quevedo (1969)
E. Marigno

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 12

Abstract
From Homage to Quevedo (1969) of the Mexican artist Jose Luis Cuevas, I present the question of the game in Francisco de Quevedo, and, especially, in the illustrations that have inspired J. L. Cuevas. I put special attention in the rewritings of Quevedo’s universe in the drawings of J. L. Cuevas. I use critical and methodological references inspired in structuralism, formalism and constructivism, to that I add the contributions of Hans Belting, George Didi-Hubermann, W. J. T. Mitchell, and of the philosophers of postmodernism like G. Deleuze or J. Derrida.
Abstract
From Homage to Quevedo (1969) of the Mexican artist Jose Luis Cuevas, I present the question of the game in Francisco de Quevedo, and, especially, in the illustrations that [...]
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Sonnets, Litanies and Praise in three Festivities in honor of the Virgin of Guadalupe (1601-1602)
B. López de Mariscal

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 6

Abstract
When relating his journey, Friar Diego de Ocaña describes two festivities celebrated in Villa de Potosí, both dedicated to the enthronement of images of the Virgin painted by himself. The festivities included processions as well as literary pieces to honor the Virgin. Ocaña notes that among the poetic texts composed in veneration and praise of the Virgin, there were also prayer-like compositions that were sung during the processions, at the end of the Eucharistic celebration, during the Salve Regina, or during those moments when the image was placed upon the altar. In the present article particular attention is given to various texts, specifically to those which accompanied the festivities that took place with the same pomp and circumstance as those ceremonies celebrated for the feast of Corpus Christ.
Abstract
When relating his journey, Friar Diego de Ocaña describes two festivities celebrated in Villa de Potosí, both dedicated to the enthronement of images of the Virgin painted [...]
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Aparición de la página "Semanas del jardín: Cervantes-Boccaccio un año en la vida de dos escritores"
M. Colón Calderón, A. Rodríguez de Ramos

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (2), 39

Abstract
Se da noticia de la aparición de la página web "Semanas del jardín: Cervantes-Boccaccio un año en la vida de dos escritores".
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Una biografía novelada de María Teresa León: «Cervantes, el soldado que nos enseñó a hablar»
C. Perugini

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (2), 29

Abstract
En la biografía novelada se juntan, aparentemente contradictorios, el aspecto documental y científico de la historia con el subjetivismo y lo imaginativo de la ficción.Las cinco biografías noveladas de María Teresa León son, en el orden: El gran amor de Gustavo Adolfo Bécquer (Buenos Aires 1946); Rodrigo Díaz de Vivar el Cid Campeador (Buenos Aires 1954); Doña Jimena Díaz del Vivar. Gran señora de todos los deberes (Buenos Aires 1960); Menesteos, marinero de abril (México 1965); Cervantes, el soldado que nos enseñó a hablar (Madrid 1978). Llaman la atención inmediatamente dos elementos comunes: el haber sido escritas todas en el exilio, incluso la de Cervantes, última obra de la autora todavía exiliada en Roma, y su dedicación a figuras marcadas por un destino malhadado y heróico, y, cada una a su manera, ejemplares.La atención hacia los clásicos, y hacia Cervantes en particular, fue una constante en la generación de intelectuales que salieron de España después de la derrota. En la biografía de María Teresa se nota una fuerte compenetración entre escritores, la moderna y el antiguo, que llegará hasta la invención de detalles existenciales del biografiado, al que la autora ofrece su voz, su manera de pensar, sus ideales.Palabras clave: María Teresa León, biografía novelada, Cervantes
Abstract
En la biografía novelada se juntan, aparentemente contradictorios, el aspecto documental y científico de la historia con el subjetivismo y lo imaginativo de la ficción.Las [...]
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Presentación
V. Roncero

Hipogrifo. Revista de literatura y cultura del Siglo de Oro (2013). Vol. 1, (1), 16

Abstract
Presentación de Hipogrifo.
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A compressible Lagrangian framework for modeling the fluid-structure interaction in the underwater implosion of an aluminum cylinder
K. Kamran, R. Rossi, E. Oñate, S. Idelsohn

Mathematical Models and Methods in Applied Sciences (2013). Vol. 23 (2), pp. 339–367

Abstract
We propose a fully Lagrangian monolithic system for the simulation of the underwater implosion of cylindrical aluminum containers. A variationally stabilized form of the Lagrangian shock hydrodynamics is exploited to deal with the ultrahigh compression shock waves that travel in both air and water domains. The aluminum cylinder, which separates the internal atmospheric-pressure air from the external high-pressure water, is modeled by a three-node rotation-free shell element. The cylinder undergoes fast transient deformations, large enough to produce self-contact along it. A novel elastic frictionless contact model is used to detect contact and compute the non-penetrating forces in the discretized domain between the mid-planes of the shell. Mesh quality in the vicinity of the cylinder is guaranteed by regenerating the mesh in the air and water domains when large displacements occur. A monolithic fluid–structure interaction (FSI) system is then solved. Two schemes are tested, implicit using the predictor/multi-corrector Bossak scheme, and explicit, using the forward Euler scheme. The results of the two simulations are compared with experimental data.
Abstract
We propose a fully Lagrangian monolithic system for the simulation of the underwater implosion of cylindrical aluminum containers. A variationally stabilized form of the Lagrangian [...]
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A portable OpenCL-based unstructured edge-based finite element Navier–Stokes solver on graphics hardware
R. Rossi, F. Mossaiby, S. Idelsohn

Computers & Fluids (2013). Vol. 81, pp. 134-144

Abstract
The rise of GPUs in modern high-performance systems increases the interest in porting portion of codes to such hardware. The current paper aims to explore the performance of a portable state-of-the-art FE solver on GPU accelerators. Performance evaluation is done by comparing with an existing highly-optimized OpenMP version of the solver. Code portability is ensured by writing the program using the OpenCL 1.1 specifications, while performance portability is sought through an optimization step performed at the beginning of the calculations to find out the optimal parameter set for the solver. The results show that the new implementation can be several times faster than the OpenMP version.
Abstract
The rise of GPUs in modern high-performance systems increases the interest in porting portion of codes to such hardware. The current paper aims to explore the performance [...]
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Migration of a generic multi-physics framework to HPC environments
P. Dadvand, R. Rossi, M. Gil, X. Martorell, J. Cotela, E. Juanpere, S. Idelsohn, E. Oñate

Computers and Fluids (2013). Vol. 80, pp. 301-309

Abstract
Creating a highly parallelizable code is a challenge specially for Distributed Memory Machines (DMMs). Moreover, algorithms and data structures suitable for these platforms can be very different from the ones used in serial code. For this reason, many programmers in the field prefer to start their own code from scratch. However, for an already existing framework supported by a long-time expertise the idea of transformation becomes attractive in order to reuse the effort done during years of development. In this presentation we explain how a relatively complex framework but with modular structure can be prepared for high performance computing with minimum modification. Kratos Multi-Physics is an open source generic multi-disciplinary platform for solution of coupled problems consist of fluid, structure, thermal and electromagnetic fields. The parallelization of this framework is performed with objective of enforcing the less possible changes to its different solver modules and encapsulate the changes as much as possible in its common kernel. This objective is achieved thanks to the Kratos design and also innovative way of dealing with data transfers for a multi-disciplinary code. This work is completed by the migration of the framework from the 86× architecture to the Marenostrum Supercomputing platform. The migration has been verified by a set of benchmarks which show high scalability, from which we present the Telescope problem in this paper.
Abstract
Creating a highly parallelizable code is a challenge specially for Distributed Memory Machines (DMMs). Moreover, algorithms and data structures suitable for these platforms [...]
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Parallel adaptive mesh refinement for incompressible flow problems
R. Rossi, J. Cotela, N. Lafontaine, P. Dadvand, S. Idelsohn

Computers and Fluids (2013). Vol. 80, pp. 342-355

Abstract
The present article describes a simple element-driven strategy for the conforming refinement of simplicial finite element meshes in a distributed environment. The proposed algorithm is effective both for local adaptive refinement and for the division of all the elements within an existing mesh. We aim to provide sufficient detail to allow the practical implementation of the algorithm, which can be coded with minimal effort provided that a distributed linear algebra library is available. The proposed refinement strategy is composed of three basic components: a global splitting strategy, an elemental splitting procedure and an error estimation technique, which are combined so to guarantee obtaining a conformant refined mesh. A number of benchmark examples show the capabilities of the proposed method. Error is estimated for the incompressible fluid-flow benchmarks using a novel indicator based on the computation of the sub-scale velocity.
Abstract
The present article describes a simple element-driven strategy for the conforming refinement of simplicial finite element meshes in a distributed environment. The proposed [...]
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A FFT preconditioning technique for the solution of incompressible flow on GPUs
M. Storti, R. Paz, L. Dalcin, S. Costarelli, S. Idelsohn

Computers and Fluids (2013). Vol. 74, pp. 44-57

Abstract
Graphic processing units have received much attention in last years. Compute-intensive algorithms operating on multidimensional arrays that have nearest neighbor dependency and/or exploit data locality can achieve massive speedups. Simulation of problems modeled by time-dependent Partial Differential Equations by using explicit time-stepping methods on structured grids is an instance of such GPU-friendly algorithms. Solvers for transient incompressible fluid flow cannot be developed in a fully explicit manner due to the incompressibility constraint. Segregated algorithms like the fractional step method require the solution of a Poisson problem for the pressure field at each time level. This stage is usually the most time-consuming one. This work discuss a solver for the pressure problem in applications using immersed boundary techniques in order to account for moving solid bodies. This solver is based on standard Conjugate Gradients iterations and depends on the availability of a fast Poisson solver on the whole domain to define a preconditioner. We provide a theoretical and numerical evidence on the advantages of our approach versus classical techniques based on fixed point iterations such as the Iterated Orthogonal Projection method.
Abstract
Graphic processing units have received much attention in last years. Compute-intensive algorithms operating on multidimensional arrays that have nearest neighbor dependency [...]
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A meshless finite point method for three‐dimensional analysis of compressible flow problems involving moving boundaries and adaptivity
R. Ortega, E. Oñate, S. Idelsohn, R. Flores

Int. J. Numer. Meth. Fluids (2013). Vol. 73 (4), pp. 323-343

Abstract
A finite point method for solving compressible flow problems involving moving boundaries and adaptivity is presented. The numerical methodology is based on an upwind‐biased discretization of the Euler equations, written in arbitrary Lagrangian–Eulerian form and integrated in time by means of a dual‐time steeping technique. In order to exploit the meshless potential of the method, a domain deformation approach based on the spring network analogy is implemented, and h‐adaptivity is also employed in the computations. Typical movable boundary problems in transonic flow regime are solved to assess the performance of the proposed technique. In addition, an application to a fluid–structure interaction problem involving static aeroelasticity illustrates the capability of the method to deal with practical engineering analyses. The computational cost and multi‐core performance of the proposed technique is also discussed through the examples provided.
Abstract
A finite point method for solving compressible flow problems involving moving boundaries and adaptivity is presented. The numerical methodology is based on an upwind‐biased [...]
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Explicit reduced‐order models for the stabilized finite element approximation of the incompressible Navier–Stokes equations
J. Baiges, R. Codina, S. Idelsohn

Int. J. Numer. Meth. Fluids (2013). Vol. 72 (12), pp. 1219-1243

Abstract
In this paper, we present an explicit formulation for reduced‐order models of the stabilized finite element approximation of the incompressible Navier–Stokes equations. The basic idea is to build a reduced‐order model based on a proper orthogonal decomposition and a Galerkin projection and treat all the terms in an explicit way in the time integration scheme, including the pressure. This is possible because the reduced model snapshots do already fulfill the continuity equation. The pressure field is automatically recovered from the reduced‐order basis and solution coefficients. The main advantage of this explicit treatment of the incompressible Navier–Stokes equations is that it allows for the easy use of hyper‐reduced order models, because only the right‐hand side vector needs to be recovered by means of a gappy data reconstruction procedure. A method for choosing the optimal set of sampling points at the discrete level in the gappy procedure is also presented. Numerical examples show the performance of the proposed strategy
Abstract
In this paper, we present an explicit formulation for reduced‐order models of the stabilized finite element approximation of the incompressible Navier–Stokes equations. [...]
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A fast and accurate method to solve the incompressible Navier‐Stokes equations
S. Idelsohn, N. Nigro, J. Gimenez, R. Rossi, J. Marti

Engineering Computations (2013). Vol. 30 (2), pp. 197-222

Abstract
Purpose – The purpose of this paper is to highlight the possibilities of a novel Lagrangian formulation in dealing with the solution of the incompressible Navier‐Stokes equations with very large time steps. Design/methodology/approach – The design of the paper is based on introducing the origin of this novel numerical method, originally inspired on the Particle Finite Element Method (PFEM), summarizing the previously published theory in its moving mesh version. Afterwards its extension to fixed mesh version is introduced, showing some details about the implementation. Findings – The authors have found that even though this method was originally designed to deal with heterogeneous or free‐surface flows, it can be competitive with Eulerian alternatives, even in their range of optimal application in terms of accuracy, with an interesting robustness allowing to use large time steps in a stable way. Originality/value – With this objective in mind, the authors have chosen a number of benchmark examples and have proved that the proposed algorithm provides results which compare favourably, both in terms of solution time and accuracy achieved, with alternative approaches, implemented in in‐house and commercial codes.
Abstract
Purpose – The purpose of this paper is to highlight the possibilities of a novel Lagrangian formulation in dealing with the solution [...]
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A domain decomposition strategy for reduced order models. Application to the incompressible Navier–Stokes equations
J. Baiges, R. Codina, S. Idelsohn

Comput. Methods Appl. Mech. Engrg., (2013). Vol. 267, pp. 23-42

Abstract
In this work, a domain decomposition strategy for non-linear hyper-reduced-order models is presented. The basic idea consists of restricting the reduced-order basis functions to the nodes belonging to each of the subdomains into which the physical domain is partitioned. An extension of the proposed domain decomposition strategy to a hybrid full-order/reduced-order model is then described. The general domain decomposition approach is particularized for the reduced-order finite element approximation of the incompressible Navier–Stokes equations with hyper-reduction. When solving the reduced incompressible Navier–Stokes equations, instabilities in the form of large gradients of the recovered reduced-order unknown at the subdomain interfaces may appear, which is the motivation for the design of additional stability terms giving rise to penalty matrices. Numerical examples illustrate the behavior of the proposed method for the simulation of the reduced-order systems, showing the capability of the approach to adapt to configurations which are not present in the original snapshot set.
Abstract
In this work, a domain decomposition strategy for non-linear hyper-reduced-order models is presented. The basic idea consists of restricting the reduced-order basis functions [...]
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Modelling of tunnelling processes and rock cutting tool wear with the particle finite element method
J. Carbonell, E. Oñate, B. Suarez

Computational Mechanics (2013). Vol. 52 (3), pp. 607-629

Abstract
Underground construction involves all sort of challenges in analysis, design, project and execution phases. The dimension of tunnels and their structural requirements are growing, and so safety and security demands do. New engineering tools are needed to perform a safer planning and design. This work presents the advances in the particle finite element method (PFEM) for the modelling and the analysis of tunneling processes including the wear of the cutting tools. The PFEM has its foundation on the Lagrangian description of the motion of a continuum built from a set of particles with known physical properties. The method uses a remeshing process combined with the alpha-shape technique to detect the contacting surfaces and a finite element method for the mechanical computations. A contact procedure has been developed for the PFEM which is combined with a constitutive model for predicting the excavation front and the wear of cutting tools. The material parameters govern the coupling of frictional contact and wear between the interacting domains at the excavation front. The PFEM allows predicting several parameters which are relevant for estimating the performance of a tunnelling boring machine such as wear in the cutting tools, the pressure distribution on the face of the boring machine and the vibrations produced in the machinery and the adjacent soil/rock. The final aim is to help in the design of the excavating tools and in the planning of the tunnelling operations. The applications presented show that the PFEM is a promising technique for the analysis of tunnelling problems.
Abstract
Underground construction involves all sort of challenges in analysis, design, project and execution phases. The dimension of tunnels and their structural requirements are [...]
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A four‐noded quadrilateral element for composite laminated plates/shells using the refined zigzag theory
A. Eijo, E. Oñate, S. Oller

Int. J. Numer. Meth. Engng. (2013). Vol. 95 (8), pp. 631-660

Abstract
A new bilinear four‐noded quadrilateral element (called quadrilateral linear refined zigzag) for the analysis of composite laminated and sandwich plates/shells based on the refined zigzag theory is presented. The element has seven kinematic variables per node. Shear locking is avoided by introducing an assumed linear shear strain field. The performance of the element is studied in several examples where the reference solution is the 3D finite element analysis using 20‐noded hexahedral elements.
Abstract
A new bilinear four‐noded quadrilateral element (called quadrilateral linear refined zigzag) for the analysis of composite laminated and sandwich plates/shells based on [...]
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A compressible Lagrangian framework for the simulation of the underwater implosion of large air bubbles
K. Kamran, R. Rossi, E. Oñate, S. Idelsohn

Comput. Methods Appl. Mech. Engrg., (2013). Vol. 255 (1), pp. 210-225

Abstract
A fully Lagrangian compressible numerical framework for the simulation of underwater implosion of a large air bubble is presented. Both air and water are considered compressible and the equations for the Lagrangian shock hydrodynamics are stabilized via a variationally consistent multiscale method. A nodally perfect matched definition of the interface is used and then the kinetic variables, pressure and density, are duplicated at the interface level. An adaptive mesh generation procedure, which respects the interface connectivities, is applied to provide enough refinement at the interface level. This framework is verified by several benchmarks which evaluate the behavior of the numerical scheme for severe compression and expansion cases. This model is then used to simulate the underwater implosion of a large cylindrical bubble, with a size in the order of cm. We observe that the conditions within the bubble are nearly uniform until the converging pressure wave is strong enough to create very large pressures near the center of the bubble. These bubble dynamics occur on very small spatial (0.3 mm), and time (0.1 ms) scales. During the final stage of the collapse Rayleigh–Taylor instabilities appear at the interface and then disappear when the rebounce starts. At the end of the rebounce phase the bubble radius reaches 50% of its initial value and the bubble recover its circular shape. It is when the second collapse starts, with higher mode shape instabilities excited at the bubble interface, that leads to the rupture of the bubble. Several graphs are presented and the pressure pulse detected in the water is compared by experiment.
Abstract
A fully Lagrangian compressible numerical framework for the simulation of underwater implosion of a large air bubble is presented. Both air and water are considered compressible [...]
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Updated Lagrangian mixed finite element formulation for quasi and fully incompressible fluids
E. Oñate, J. Carbonell

(2013). Research Report, Nº PI393

Abstract
We present a mixed velocity-pressure finite element formulation for solving the updated Lagrangian equations for quasi and fully incompressible fluids. Details of the governing equations for the conservation of momentum and mass are given in both differential and variational form. The finite element interpolation uses an equal order approximation for the velocity and pressure unknowns. The procedure for obtaining stabilized FEM solutions is outlined. The solution in time of the discretized governing conservation equations using an incremental iterative segregated scheme is described. The linearization of these equations and the derivation of the corresponding tangent stiffness matrices is detailed. Other iterative schemes for the direct computation of the nodal velocities and pressures at the updated configuration are presented. The advantages and disadvantages of choosing the current or the updated configuration as the reference configuration in the Lagrangian formulation are discussed.
Abstract
We present a mixed velocity-pressure finite element formulation for solving the updated Lagrangian equations for quasi and fully incompressible fluids. Details of the governing [...]
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A comparative study on homogenization strategies for multi-scale analysis of materials
J. Ortolano, J. Hernández, J. Oliver

Monograph CIMNE (2013). M135

Abstract
One of the most important engineering tasks over the years has been the design and manufacture of increasingly sophisticated structural materials as a result of the requirements related to the technological progress. In the last decades, the growing needs for improved properties of products have been partially solved through the development of composite materials. A key to the success of many modern structural components is the tailored behavior of the material to given applications. Therefore, research efforts in material science engineering have been focused in the design of new materials either through the creation of new structures at the scale of single atoms and molecules or through the development of structural materials by changing the composition, size, arrangement and topology of the constituents at larger scales: the microscopic/mesoscopic level. The development of new materials has been linked to the development of a new theoretical field within the mechanics of solids. This branch of the mechanical, known as Continuum Micromechanics, introduces a series of new concepts that are key to the definition of the macroscopic properties of composite materials on the basis of the definition of the characteristics of its components. Starting from the premise of separation of scales and the concept of Representative Volume Element, defined the so-called homogenization methods, whose number has been increasing as the Micromechanics is gone extend over the years. Such methods are many and varied, although especially there have been two that have been used and developed by the majority of authors: the so-called Mean-Homogenization techniques and the multi-scale based on Finite Element Approaches. Mean-fifieeld homogenization schemes are an efficient way to predict the behavior of heterogeneous materials. They range from the simplest hypotheses of the stress or strain sharing among the phases which do not require analytical solution on the associated boundary-value problem to more involved geometric models based on the solution of a boundary-value problem involving a single or composite inclusion embedded in an equivalent homogenized medium whose elastic module become part of the solution procedure. In general, they are based on analytical solutions of the boundary value problem defined in the microstructure level of the inhomogeneous material and provide good predictions for the mean values over the RVE. Although originally designed for elastic materials, some approaches to deal with elastoplastic materials and even with viscoplastic materials have been developed over the years and compared with the results obtained using Finite Element Approaches. The comparison between different methods of homogenization allows the definition of a range of validity between the different methods, which helps to discover the limitations of the various methods and aspects to take into account for future developments and research. The main goal of this work is, firstly, to present a general overview of the different techniques that have been developed in the last years in order to obtain a prediction of the behavior of elastoplastic composites by taking into account geometrical and mechanical aspects. Secondly, a comparison between the different approaches is carried out through a numerical implementation of such techniques. Both objectives will be carried out through eight different chapters. The first chapter serves as an introduction and historical review of the advances that have been made in the field of micromechanics. On the other hand, the second chapter deals with some important theoretical background that is important in the field of Continuum Micromechanics, as well as a short introduction of the different approaches that traditionally have been considered to solve the problem. One group of methods, based on analytical solutions { the so-called Mean Field Analysis { will be commented in chapter 3. Chapter 4 is devoted to the implementation and validation of a numerical tool that solves the mean-field homogenization using analytical schemes for elastoplastic materials. Subsequent chapters are devoted to the comparison of the results with the results given by the Finite Element Method. The general formulation of such method { applied to multi-scale problems { is presented in chapter 5 from a theoretical point of view, as well as the corresponding numerical examples. Finally, last chapter will be dedicated to enumerate some conclusions extracted from the present work, including some aspects that can be object of future works or improvements. The current work presents some important aspects about the theoretical concepts and the numerical implementation of some key approaches for solving the mechanical problem regarding composite materials. There exist a large number of possibilities to approximate the response of such complex materials, based in different assumptions. This document shows the general efficiency of the so-called mean-field homogenization schemes to capture correctly the macroscopic behavior of composites. Although these techniques show some limitations, like the incapability to provide results for the distribution of the different variables over the microgeometry or the low accuracy in the case of complex microgeometries (like porous materials), they represent an efficient way to predict the main general behavior of a composite material spending low computational effort. They are specially indicated to be used in the previous steps of an analysis or as a tool to validate the results with more involved approaches.
Abstract
One of the most important engineering tasks over the years has been the design and manufacture of increasingly sophisticated structural materials as a result of the requirements [...]
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Mechanistic and pathological study of the genesis, growth and rupture of abdominal aortic aneurysms
E. Soudah, M. Bordone, E. Kwee, T. Loong, C. Tan, P. Uei, N. Sriram

Monograph CIMNE (2013). M137

Abstract
The aim of this document is to report the study process and the work carried on by CIMNE, in order that NTU and TTSH can validate the AAA results obtained during this analysis. The structure of this numerical analysis will be used for the following cases.
Abstract
The aim of this document is to report the study process and the work carried on by CIMNE, in order that NTU and TTSH can validate the AAA results obtained during this analysis. [...]
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Investigación sobre el diseño de protecciones tipo repié para evitar el deslizamiento en masa de presas de escollera sometidas a perculaciones extremas
R. Morán, M. Toledo

Monograph CIMNE (2013). M138

Abstract
Este trabajo es el fruto de una tesis doctoral cuyo objetivo principal es definir criterios de diseño de protecciones en forma de repié en presas de materiales sueltos cuyo espaldón de aguas abajo esté formado por escollera. La protección propuesta consiste en un relleno de material granular situado sobre el pie de aguas abajo de la presa y formado a su vez por una escollera con características diferenciadas respecto de la escollera que integra el espaldón de la presa. La función de esta protección es evitar que se produzcan deslizamientos en masa cuando una cantidad de agua anormalmente elevada circula accidentalmente por el espaldón de aguas abajo de la presa por distintos motivos como pueden ser el vertido por coronación de la presa o la pérdida de estanqueidad del elemento impermeable o del cimiento. Según los datos de la International Commission on Large Dams (ICOLD 1995) el 70% de las causas de rotura o avería grave en presas de materiales sueltos en el mundo están dentro de las que se han indicado con anterioridad. Esta circulación accidental de agua a través del espaldón de escollera, típicamente turbulenta, se ha denominado en este trabajo percolación (“through flow”, en inglés) para diferenciarla del término filtración, habitualmente utilizada para el flujo laminar a través de un material fino. El fenómeno físico que origina la rotura de presas de materiales sueltos sometidas a percolación accidental es complejo, entrando en juego diversidad de parámetros, muchas veces no deterministas, y con acoplamiento entre procesos, tanto de filtración como de arrastre y deslizamiento. A lo largo de la investigación se han realizado diferentes estudios experimentales y numéricos con objeto de analizar el efecto sobre el nivel de protección frente al deslizamiento en masa que producen los principales parámetros geométricos que definen el repié: la anchura de la berma, el talud exterior y su altura máxima desde la base. También se han realizado estudios sobre factores con gran influencia en el fenómeno de la percolación como son la anisotropía del material y el incremento de los caudales unitarios en el pie de presa debidos a la forma de la cerrada. A partir de los resultados obtenidos en las distintas campañas de modelación física y numérica se han obtenido conclusiones respecto a la efectividad de este tipo de protección para evitar parcial o totalmente los daños provocados por percolación accidental en presas de escollera. El resultado final del trabajo es un procedimiento de diseño para este tipo de protecciones. Con objeto de completar los criterios de dimensionamiento, teniendo en cuenta los mecanismos de rotura por erosión interna y arrastre, se han incluido dentro del procedimiento recomendaciones adicionales basadas en investigaciones existentes en la bibliografía técnica. Finalmente, se han sugerido posibles líneas de investigación futuras para ampliar el conocimiento de fenómenos complejos que influyen en el comportamiento de este tipo de protección como son el efecto de escala, la anisotropía de la escollera, las leyes de resistencia que rigen la filtración turbulenta a través de medios granulares, los efectos de cimentaciones poco competentes o la propia caracterización de las propiedades de la escollera de presas.
Abstract
Este trabajo es el fruto de una tesis doctoral cuyo objetivo principal es definir criterios de diseño de protecciones en forma de repié en presas de materiales [...]
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Multified-based modeling of material failure in high performance reinforced cementitious composites
D. Mora, J. Oliver, A. Huespe

Monograph CIMNE (2013). M139

Abstract
Cementitious materials such as mortar or concrete are brittle and have an inherent weakness in resisting tensile stresses. The addition of discontinuous fibers to such matrices leads to a dramatic improvement in their toughness and remedies their deficiencies. It is generally agreed that the fibers contribute primarily to the post-cracking response of the composite by bridging the cracks and providing resistance to crack opening (Suwaka & Fukuyama 2006). On the other hand, the multifield theory is a mathematical tool able to describe materials which contain a complex substructure (Mariano & Stazi 2005). This substructure is endowed with its own properties and it interacts with the macrostructure and influences drastically its behavior. Under this mathematical framework, materials such as cement composites can be seen as a continuum with a microstructure. Therefore, the whole continuum damage mechanics theory, incorporating a new microstructure, is still applicable. A formulation, initially based on the theory of continua with microstructure Capriz (Capriz 1989), has been developed to model the mechanical behavior of the high performance fiber cement composites with arbitrarily oriented fibers. This formulation approaches a continuum with microstructure, in which the microstructure takes into account the fibermatrix interface bond/slip processes, which have been recognized for several authors (Li 2003, Naaman 2007b) as the principal mechanism increasing the ductility of the quasi-brittle cement response. In fact, the interfaces between the fiber and the matrix become a limiting factor in improving mechanical properties such as the tensile strength. Particularly, in short fiber composites is desired to have a strong interface to transfer effectively load from the matrix to the fiber. However, a strong interface will make difficult to relieve fiber stress concentration in front of the approaching crack. According to Naaman (Naaman 2003), in order to develop a better mechanical bond between the fiber and the matrix, the fiber should be modified along its length by roughening its surface or by inducing mechanical deformations. Thus, the premise of the model is to take into account this process considering a microfield that represents the slipping fiber-cement displacement. The conjugate generalized stress to the gradient of this micro-field verifies a balance equation and has a physical meaning. This contribution includes the computational modeling aspects of the high fiber reinforced cement composites (HFRCC) model. To simulate the composite material, a finite element discretization is used to solve the set of equations given by the multifield approach for this particular case. A two field discretization: the standard macroscopic and the microscopic displacements, is proposed through a mixed finite element methodology. Furthermore, a splitting procedure for uncoupling both fields is proposed, which provides a more convenient numerical treatment of the discrete equation system. The initiation of failure in HPFRCC at the constitutive level identified as the onset of strain localization depends on the mechanical properties of the all compounds and not only on the matrix ones. As localization criteria is considered the bifurcation analysis in combination with the localized strain injection technique presented by Oliver et al. (Oliver et al. 2010a). It consists of injecting a specific localization mode during the localization stage, via mixed finite element formulations, to the path of elements that are going to capture the cracks, and, in this way, the spurious mesh orientation dependence is removed. Model validation was performed using a selected set of experiments that proves the viability of this approach. The numerical examples of the proposed formulation illustrated two relevant aspects, namely: 1) the role of the bonding mechanism in the strain hardening behavior after cracking in the HPFRCC and 2) the role that plays the finite element formulation in capturing the displacement localization in the localization stage.
Abstract
Cementitious materials such as mortar or concrete are brittle and have an inherent weakness in resisting tensile stresses. The addition of discontinuous fibers to such matrices [...]
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A compressible Lagrangian framework for the simulation of underwater implosion problems
K. Kamran, E. Oñate, S. Idelsohn, R. Rossi

Monograph CIMNE (2014). M150

Abstract
The development of efficient algorithms to understand implosion dynamics presents a number of challenges. The foremost challenge is to efficiently represent the coupled compressible fluid dynamics of internal air and surrounding water. Secondly, the method must allow one to accurately detect or follow the interface between the phases. Finally, it must be capable of resolving any shock waves which may be created in air or water during the final stage of the collapse. We present a fully Lagrangian compressible numerical framework for the simulation of underwater implosion. Both air and water are considered compressible and the equations for the Lagrangian shock hydrodynamics are stabilized via a variationally consistent multiscale method. A nodally perfect matched definition of the interface is used and then the kinetic variables, pressure and density, are duplicated at the interface level. An adaptive mesh generation procedure, which respects the interface connectivities, is applied to provide enough refinement at the interface level. This framework is then used to simulate the underwater implosion of a large cylindrical bubble, with a size in the order of cm. Rapid collapse and growth of the bubble occurred on very small spatial (0.3mm), and time (0.1ms) scales followed by Rayleigh-Taylor instabilities at the interface, in addition to the shock waves traveling in the fluid domains are among the phenomena that are observed in the simulation. We then extend our framework to model the underwater implosion of a cylindrical aluminum container considering a monolithic fluid-structure interaction (FSI). The aluminum cylinder, which separates the internal atmospheric-pressure air from the external high-pressure water, is modeled by a three node rotation-free shell element. The cylinder undergoes fast transient deformations, large enough to produce self-contact along it. A novel elastic frictionless contact model is used to detect contact and compute the non-penetrating forces in the discretized domain between the mid-planes of the shell. Two schemes are tested, implicit using the predictor/multi-corrector Bossak scheme, and explicit, using the forward Euler scheme. The results of the two simulations are compared with experimental data.
Abstract
The development of efficient algorithms to understand implosion dynamics presents a number of challenges. The foremost challenge is to efficiently represent the coupled compressible [...]
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Congresos y seminarios
L. Suárez

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Congresos y Seminarios
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Manejo de elementos finitos para modelar estructuras de paviemnto en o cerca de la falla usando un método de módulo volumétrico constante
C. González, M. Santiago

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Hoy día se requiere que ingenieros militares implementen metodologías de diseño capaces de predecir el rendimiento de los pavimentos basado en información de campo limitada. Investigadores del U.S. Army Engineer Research and Development Center (ERDC) han desarrollado un método de modelaje simplificado, el cual se ha implementado en los criterios de diseño. En este método se asume que los materiales mantienen un módulo volumétrico constante mientras que el módulo de elasticidad y la razón de Poisson varían a medida que el elemento se aproxima a la falla. Estas suposiciones previenen el colapso de los elementos a medida que se aproximan a la falla, forzando al material a fallar en cortante. Este artículo resume el método técnico, incluyendo la validación del procedimiento usando simulaciones de pruebas de laboratorio conducidas en materiales de pavimento y pruebas de campo conducidas en secciones de pavimentos de aeropuertos de escala real. Las predicciones de rendimiento de pavimentos usando este método proveyeron una conformidad razonable con los esfuerzos observados bajo cargas de aviones en el campo. Basado en los resultados de este estudio, este método será utilizado para desarrollar criterios nuevos de diseño de pavimentos militares.
Abstract
Hoy día se requiere que ingenieros militares implementen metodologías de diseño capaces de predecir el rendimiento de los pavimentos basado en información de campo limitada. [...]
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Evaluación del efecto de la humedad en mezclas asfálticas tibias al utilizar los aditivos Rediset y Sasobit
F. Martínez, M. Estrada

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Debido a los cambios climáticos que generan humedad en las zonas tropicales, el pavimento presenta cierta susceptibilidad a fallar por el desprendimiento de la película asfáltica. Este artículo presenta la metodología utilizada al evaluar el efecto de la humedad en mezclas asfálticas tibias, las cuales fueron modificadas por los aditivos Rediset (manufacturado por Akzonobel) y Sasobit (manufacturado por Sasol) añadidos directamente al asfalto líquido. Las mezclas compactadas fueron sometidas a un ciclo de 24 horas a temperaturas de 0°F y 140°F conocidas como ciclos frío y caliente, respectivamente, con el propósito de aplicar tensión indirecta al espécimen. La prueba permite obtener una razón conocida como ?tensile strength ratio?, la cual debe ser mayor de 80% como evidencia de que no se presentará el efecto de ?stripping? en la mezcla. Los resultados mostraron que ambos aditivos reducen la susceptibilidad a la humedad de la mezcla compactada disminuyendo así la probabilidad de que ocurra pérdida de la película asfáltica.
Abstract
Debido a los cambios climáticos que generan humedad en las zonas tropicales, el pavimento presenta cierta susceptibilidad a fallar por el desprendimiento de la película [...]
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Historias de éxito en Puerto Rico utilizando tecnologías impulsadas por el programa cada día cuenta (EDC, por sus siglas en inglés)
M. Pérez

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
La Administración Federal de Carreteras (FHWA, por sus siglas en inglés) del Departamento de Transportación Federal de los Estados Unidos estableció un programa innovador a nivel nacional denominado Cada Día Cuenta (EDC, por sus siglas en inglés). Las metas principales de este programa son reducir el tiempo de ejecución de proyectos de carreteras, mejorar la seguridad en las carreteras y proteger el medio ambiente. Esta ponencia describe cinco iniciativas del programa Cada Día Cuenta que han sido implantadas en Puerto Rico por el Departamento de Transportación y Obras Públicas (DTOP) y la Autoridad de Carreteras y Transportación (ACT), a saber, Mezclas Tibias de Asfalto (WMA); Elementos y Sistemas Prefabricados para la Construcción de Puentes (PBES); Controles Adaptivos de Semáforos (ASCT); Bordes de Seguridad en Pavimentos (SE); y Suelos Reforzados con Geosintéticos-Sistema Integrado de Puentes (GRS-IBS). Los beneficios asociados a la implantación de estas iniciativas también se describen en la ponencia.
Abstract
La Administración Federal de Carreteras (FHWA, por sus siglas en inglés) del Departamento de Transportación Federal de los Estados Unidos estableció un programa innovador [...]
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La influencia de elementos de la carretera en velocidades operacionales a lo largo de zonas de transición usando el método de regresión basada en el árbol jerárquico
Y. Cruz-Cantillo, I. Cruzado

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Los segmentos de carreteras que unen las zonas de alta velocidad con las zonas de baja velocidad son conocidos como zonas de transición; es en estas zonas que los conductores deben ajustar sus velocidades operacionales. La seguridad en las zonas de transición estará comprometida si los conductores no reducen la velocidad antes de entrar a la zona de baja velocidad. Un estudio fue llevado a cabo con el propósito de identificar las características geométricas de la carretera que influyen el comportamiento de los conductores según datos de velocidades antes, durante y después de diversas zonas de transición. Datos de velocidades y detalles geométricos de la carretera fueron tomados en zonas de transición de carreteras rurales de dos carriles en Pennsylvania. Los datos tomados fueron analizados con el modelo estadístico Regresión Basada en Árbol Jerárquico (RBAJ) y los resultados indican que la velocidad máxima postulada de 25mph es la variable que mayor predice las velocidades a lo largo de las zonas de transición.
Abstract
Los segmentos de carreteras que unen las zonas de alta velocidad con las zonas de baja velocidad son conocidos como zonas de transición; es en estas zonas que los conductores [...]
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Modelo de toma de decisión al inicio del período de amarillo en intersecciones semaforizadas
F. González, A. Medina

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Las infracciones a la señal roja ("Red-Light Running", RLR) en una intersección con semáforo es un grave problema de seguridad. Un estudio de estos eventos fue llevado a cabo mediante el uso de tres cámaras de vídeo grabando de manera sincronizada la trayectoria de los vehículos de motor arribando a una intersección y el comportamiento de los conductores al inicio del período de cambio de la señal amarilla en una intersección del Municipio de Mayagüez en Puerto Rico. El estudio encontró que los tiempos promedio de entrada en los períodos de amarillo y de rojo en la intersección fueron de 3.00 segundos y 2.46 segundos, respectivamente, demostrando un alto nivel de agresividad de los conductores. Los análisis realizados demuestran la importancia de poder conocer la posición y la velocidad de los vehículos arribando a la intersección para estimar la probabilidad de que un conductor decida detenerse o seguir a través de la intersección. Modelos para estimar el tiempo de entrada en amarillo y la probabilidad de que un vehículo de motor siga o se detenga al inicio del período de amarillo fueron calibrados con datos recopilados de la distancia y la velocidad de los vehículos llegando a la intersección al momento del cambio de la señal.
Abstract
Las infracciones a la señal roja ("Red-Light Running", RLR) en una intersección con semáforo es un grave problema de seguridad. Un estudio de [...]
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Programa de seguridad física y pública en el transporte público: Caso del sistema de carros públicos de Puerto Rico
M. Rodríguez

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Durante los pasados años, el gobierno federal ha requerido que las autoridades de transporte público informen sobre incidencias de seguridad en sus servicios de transportación. Por tal motivo se ha desarrollado un programa para registrar incidentes de este tipo y poblar una base de datos con detalles de los eventos de seguridad del servicio de transporte público desde las perspectivas de seguridad física y seguridad pública. Los eventos de seguridad física son aquellos que surgen por accidente y atentan contra la integridad física de los integrantes del sistema (usuarios y empleados). Los eventos de seguridad pública son aquellos que atentan contra la integridad del sistema de transportación e incluye actividades delictivas sobre el sistema y sus integrantes (usuarios y empleados). La base de datos contiene seis años de información y se utiliza para presentar información a nivel global sobre la incidencia de eventos de seguridad pública y seguridad física. Luego, los datos son normalizados utilizando las estadísticas de servicio y patrocinio para identificar tendencias temporales en la cantidad y severidad de los eventos. En este documento, se presenta como caso de estudio el sistema de carros públicos de Puerto Rico. Según los resultados de este programa, este sistema de transporte público tiene una tendencia alcista en la incidencia de choques vehiculares y en la severidad de estos incidentes, lo que lo hace cada vez más inseguro y riesgoso desde la perspectiva de integridad física para el usuario y para los propios operadores del servicio.
Abstract
Durante los pasados años, el gobierno federal ha requerido que las autoridades de transporte público informen sobre incidencias de seguridad en sus servicios de transportación. [...]
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Desarrollo e implantación de un plan sistemático de seguridad vial
C. Aponte, J. Ortiz

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Con el tiempo hemos observado como el sistema vial de Puerto Rico se ha desarrollado. Desde las vías de mayor importancia en décadas pasadas, como la PR-1, PR-2 y PR-3; hasta nuestros expresos del presente PR-22, PR-52, PR-53 y PR-66; se ha documentado el esfuerzo por parte del Departamento de Transportación y Obras Públicas (DTOP) en el tema de la Seguridad Vial. En los pasados años, el número de fatalidades en la Isla ha descendido desde 519 para el año 2002 hasta 359 en el 2011. Este documento describe las estrategias de ingeniería implantadas en Puerto Rico para lograr tal descenso en las fatalidades. Aún cuando los ingenieros de transportación no han realizado un análisis detallado de choques de tránsito por la ausencia de datos actuales, se ha desarrollado un Plan de Seguridad Vial basado en modernizar los sistemas y elementos de transportación.
Abstract
Con el tiempo hemos observado como el sistema vial de Puerto Rico se ha desarrollado. Desde las vías de mayor importancia en décadas pasadas, como la PR-1, PR-2 y PR-3; [...]
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La complejidad del problema de la inseguridad vial: Cómo explicarlo y cómo enfrentarlo
H. Ordóñez

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
En esta ponencia se presenta la complejidad de la problemática de la inseguridad vial y las diferentes ramificaciones de manera específica y pragmática. Además, desde el ámbito de la complejidad, se enumeran una serie de interrogantes que deben atenderse y los principios básicos para mejorar la seguridad vial para dar respuesta a dichas interrogantes. A estos efectos, se describe una propuesta metodológica aplicando los aspectos conceptuales para poder disponer un conjunto de estrategias mediante una aproximación multidimensional al sistema. Dicha aproximación metodológica identifica los factores críticos de riesgo y su interrelación basada en la planeación estratégica situacional (PES) desarrollado por el economista chileno Carlos Matus. Se presenta, además, el mapa general de factores de riesgo y su interrelación que generan la problemática de inseguridad vial. Por último, se presentan una serie de estrategias para enfrentar la problemática de la inseguridad vial con eficacia en el corto plazo.
Abstract
En esta ponencia se presenta la complejidad de la problemática de la inseguridad vial y las diferentes ramificaciones de manera específica y pragmática. [...]
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La seguridad en la infraestructura vial: Un compromiso de todos
B. Ríos

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (1)

Abstract
Editorial: La seguridad en la infraestructura vial: Un compromiso de todos
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Investigación de causas de explosiones en una planta de almacenamiento de combustible en Puerto Rico
J. Abreu, L. Godoy

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
Errata "Investigación de causas de explosiones en una planta de almacenamiento de combustible en Puerto Rico"
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Evaluacion de la erosión en limos loessicos compactados a través de ensayos de filtración
M. Zeballos, A. Adami, R. Terzariol, R. Rocca

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
El limo arenoso de las formaciones loéssicas se caracteriza por su alta sensibilidad a los cambios de humedad. Esta condición lo cataloga como internamente inestable. A pesar de calificación, se constituye, en un material aplicable a diversas construcciones (viales e hidráulicas). Algunas referencias bibliográficas cuestionan la aplicación de estos materiales en obras de infraestructura debido a su potencialidad de erosión. En otros casos, se indica que, para un adecuado funcionamiento el sistema debe contar con filtros de protección. En particular, los limos arenosos estudiados pueden considerarse incluidos en el grupo de aquellos materiales pasibles de sufrir procesos de sufusión, o inestabilidad interna de la estructura del suelo. En consecuencia, es de interés entender bajo qué condiciones se produce la erosión y que magnitud puede alcanzar. Si se aplica un filtro, el mismo debe actuar controlando la perdida de material y asegurando la estabilidad del flujo. Este estudio muestra los resultados experimentales del análisis del fenómeno de erosión en limos loéssicos con bajo nivel de compactación. Se han efectuado ensayos de filtración para la evaluación de la erosión y para el estudio de comportamiento de los sistemas suelo-filtro. La metodología de ensayo aplicada procura el seguimiento de los lineamientos de estudio que actualmente se discuten a nivel mundial. Los estudios se han concentrado en el análisis de la influencia de variables tales como: grado de compactación, gradiente hidráulico y composición del material de filtro. Los resultados obtenidos permiten establecer lineamientos de recomendaciones de aplicación en referencia al comportamiento esperado y la constitución de los sistemas de filtro, a fin de controlar adecuadamente la sufusión.
Abstract
El limo arenoso de las formaciones loéssicas se caracteriza por su alta sensibilidad a los cambios de humedad. Esta condición lo cataloga como internamente inestable. A [...]
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Diseño sísmico de marcos no dúctiles de concreto reforzado con disipadores de energía histeréticos: Definición de parámetros de diseño
A. Tena Colunga, H. Hernández

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
En este trabajo los autores resumen los resultados de un estudio paramétrico dedicado a evaluar, mediante análisis estáticos no lineales (pushover), parámetros globales de diseño sísmico que puedan insertarse transparentemente al Apéndice A de NTCS-04 y al Manual de Obras Civiles (MOC-2008) vigentes, para marcos de concreto reforzado no dúctiles con dispositivos de disipación de energía por histéresis montados en contraventeo chevrón. Para ello se diseñaron marcos cuyas alturas oscilaron entre 5 y 25 niveles utilizando diferentes balances de rigidez entre el sistema contraviento-dispositivo histerético y el marco resistente a momento (α). También, se consideraron diferentes balances de rigidez elástica entre el disipador histerético y los contravientos de soporte (β). Además, a partir de los resultados observados en distintas investigaciones experimentales con este tipo de dispositivos, se evaluaron las pendientes posteriores a fluencia (K2) de los disipadores, incluyendo aquéllos que se idealizan como elastoplásticos perfectos, y para pendientes de 3% y 5%. Por último, se consideraron dos ángulos de inclinación de los contravientos con respecto al eje horizontal (θ): 40° y 45°, considerando alturas de entrepiso y claros típicos usados en la práctica ingenieril mexicana. De los resultados obtenidos en el estudio se definen balances "óptimos" de rigidez α y β que lideran a obtener mecanismos últimos satisfactorios donde los disipadores por histéresis fluyen primero y desarrollan su máxima ductilidad por desplazamiento μ, mientras que en el marco de concreto reforzado se desarrollan solamente fluencias incipientes en los extremos de las vigas. Finalmente, se hacen comentarios adicionales en relación con: (a) las relaciones entre la capacidad de ductilidad global (Q) del sistema y la ductilidad local de los disipadores histeréticos (μ) para una combinación determinada de α, β, K2 y θ, (b) las distorsiones de entrepiso y su relación con el balance de rigidez seleccionado α y, (c) factores de sobrerresistencia (R) para fines de diseño.
Abstract
En este trabajo los autores resumen los resultados de un estudio paramétrico dedicado a evaluar, mediante análisis estáticos no lineales (pushover), parámetros [...]
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Observaciones sobre la predicción de sismos: Una visión actual
E. Tapia-Hernandez

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
El presente artículo estudia la factibilidad de efectuar predicciones de sismos, así como el estado actual de los estudios relacionados con sustento científico. El artículo centra su atención en métodos basados en precursores físicos que consideran observaciones directas, métodos basados en patrones estadísticos, catálogos históricos para establecer los requisitos mínimos que deben considerarse para identificar métodos objetivos para la predicción de sismos. El artículo discute distribuciones de probabilidad para sismos en México a partir de registros históricos.
Abstract
El presente artículo estudia la factibilidad de efectuar predicciones de sismos, así como el estado actual de los estudios relacionados con sustento científico. El artículo [...]
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Determinação e padronização de parâmetros do solo para disposição de resíduos sólidos
F. Oliveira, M. Alves, C. Oliveira

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
O presente trabalho visou determinar e padronizar parâmetros do solo, para avaliação de áreas para disposição de resíduos provenientes das atividades humanas, levando-se em consideração a maneira como cada fator interfere na disposição e seu comportamento em contato com o solo. Áreas classificadas como latossolos foram consideradas as mais adequadas e espodossolos, gleissolos e organossolos os menos adequados para a disposição de resíduos. Os Depósitos de Formação Barreiras foram considerados de adequabilidade máxima, por serem solos situados em regiões de relevo mais abatido, tendo, portanto maiores espessuras dos solos em avançado estágio de intemperização, muito evoluídos, bem drenados e com relevo aplainado. Os resultados obtidos no presente trabalho revelam as características desejáveis dos solos para áreas de disposição de resíduos sólidos, características essas que podem ser alteradas de acordo com a infra-estrutura proposta para a área.
Abstract
O presente trabalho visou determinar e padronizar parâmetros do solo, para avaliação de áreas para disposição de resíduos provenientes das atividades humanas, levando-se [...]
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Revision de velocidades de viento extremas en tres localidades del sur de Argentina
B. Natalini, M. Natalini

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
La valoración de la acción del viento sobre un edificio en la etapa de diseño requiere conocer la magnitud de las máximas velocidades de viento a las que estará expuesta la estructura durante su vida útil. En la práctica profesional, esta información se extrae del llamado mapa de vientos, que es parte de los reglamentos nacionales de acción del viento sobre estructuras civiles. En Argentina, el reglamento pertinente es el CIRSOC 102. Si bien fue editado en 2005, el mapa de vientos que trae este reglamento se basa principalmente en información meteorológica del período entre 1970 y 1990. En este trabajo se discute la metodología usada para construir este mapa, a la luz de procedimientos más actualizados desarrollados en los últimos 20 años. Se ilustra la discusión aplicando algunos de estos nuevos procedimientos a registros de tres estaciones meteorológicas de zonas donde el clima está dominado por depresiones y se muestra la conveniencia de actualizar el mapa.
Abstract
La valoración de la acción del viento sobre un edificio en la etapa de diseño requiere conocer la magnitud de las máximas velocidades de viento a las que estará expuesta [...]
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Diseño de infraestructura para la protección de la erosión costera en el litoral argentino: Caso de Mar del Plata
P. Gyssels, M. Ragessi, A. Rodriguez, J. Cardini, M. Campos

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
El frente costero urbano al sur de Punta Mogotes (Mar del Plata, Buenos Aires) padece desde hace años un fenómeno de erosión progresiva debido a factores naturales y de origen antrópico. En este trabajo se ha realizado un anteproyecto de una infraestructura de protección costera. El diseño prevé la construcción de una serie de diques exentos paralelos a la costa. Para ello se ha estudiado la hidrodinámica y la dinámica sedimentaria, para la situación de diseño final y también para la situación actual. El análisis se realizó a diferentes escalas espacio-temporales: a corto plazo (horas) y a largo plazo (meses y años). Los resultados indican que el esquema propuesto funcionaría adecuadamente protegiendo la costa, sin la formación de tómbolos.
Abstract
El frente costero urbano al sur de Punta Mogotes (Mar del Plata, Buenos Aires) padece desde hace años un fenómeno de erosión progresiva debido a factores naturales y de [...]
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La carencia de uniformidad en el riesgo de carreteras en zonas montañosas
R. Rocca, M. Herz

International Journal of Natural Disasters, Accidents and Civil Infrastructure (2013). Vol. 13, (2)

Abstract
Editorial: La carencia de uniformidad en el riesgo de carreteras en zonas montañosas
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Accelerated 3D multi-body seakeeping simulations using unstructured finite elements
B. Servan Camas, J. García-Espinosa

Journal of Computational Physics (2013). 252:382-403 (preprint)

Abstract
Being capable of predicting seakeeping capabilities in the time domain is of great interest for the marine and offshore industry. However, most computer programs used in the industry work in the frequency domain, with the subsequent limitation in the accuracy of their model predictions. The main objective of this work is the development of a time domain solver based on the finite element method capable of solving multi-body seakeeping problems on unstructured meshes. In order to achieve such an objective, several techniques are combined: the use of an efficient algorithm for the free surface boundary conditions, the use of deflated conjugate gradients, and the use of a graphic processing unit for speeding up the linear solver. The results obtained results by the developed model showed good agreement with analytical solutions, experimental data for an actual offshore structure model, as well as numerical solutions obtained by other numerical method. Also, a simulation with sixteen floating bodies was carried out in a affordable CPU time, showing the potential of this approach for multi-body simulation.
Abstract
Being capable of predicting seakeeping capabilities in the time domain is of great interest for the marine and offshore industry. However, most computer programs used in the [...]
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Relation between the raise to span ratio and the real ultimate lateral strength for parabolic clamped arches considering different calculation hypothesis
J. Japón, I. Sánchez-Barbudo

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (3)

Abstract
Curved graphs that relate the f/L ratio and the λ = qL3 /EIy parameter for clamped arches with the different calculation hypothesis are going to be proposed in this article. It has been necessary to determine the real critical lateral strength of a series of clamped arches considering different calculation hypothesis respect to geometrical linearity and a steel material characteristic. The elastic-plastic material hypothesis with non geometrical linearity considers the existence of residual stresses and initial lateral deflection.
Abstract
Curved graphs that relate the f/L ratio and the λ = qL3 /EIy parameter for clamped arches with the different calculation hypothesis are going to be proposed in this article. [...]
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Finite layer method for retaining walls with flexible foundation under seismic excitation
I. Bonola, J. Avilés

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)

Abstract
A finite layer method for evaluation of the effects of seismic action on retaining walls is presented, which is based on the wave propagation theory and modal superposition. The system is defined by a rigid wall supported on an elastic stratum, with capacity of sliding and overturning of the base. With this model, the foundation flexibility as well as the energy dissipation by wave radiation is considered. It is demonstrated with numerical results that the magnitude of pressures on the wall depends on its movement capacity.
Abstract
A finite layer method for evaluation of the effects of seismic action on retaining walls is presented, which is based on the wave propagation theory and modal superposition. [...]
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Elastoplastic Analysis of Framed Structures with Interaction Surfaces Obtained for Multiple Linear Regression
P. Vieira, W. Matias Silva

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (3)

Abstract
The ultimate limit state criteria (yielding surfaces) applied to structural designs are easier in stress resultants. There are many difficulties to generating interaction surfaces with six sectional efforts obtained through to numerical or experimental models of a space-frame analysis. The approach, in the literature, to nonlinear analysis of structures with 3D beams is use of interaction surfaces with only three combined efforts in the cross-section. Therefore, a better understanding of load types, of interactions between the six efforts and of local and global stability of structure are necessary. The interaction surfaces with three efforts are presented in planes, quadrics, more complex, or a mixture of them shapes, so that techniques which use analytical formulations with combined efforts and several section shapes are more or less complex. Multiple linear regression allows to treat the resultant efforts of several analyses for obtaining a yielding surface with the combined efforts. In this paper, the formulation to obtaining of the surfaces and their applications in the analysis of elasto-plastic frame structures are presented.
Abstract
The ultimate limit state criteria (yielding surfaces) applied to structural designs are easier in stress resultants. There are many difficulties to generating interaction [...]
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Efficient calculation of formation energies of kink-pairs in BCC crystals
E. Tellechea, O. Sabri, M. Ariza

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (3)

Abstract
Motion of screw dislocations in BCC materials at low temperature is believed to be related to the formation of mobile kinks on the dislocation line. Therefore, the accurate prediction of kink nucleation energies is required to fully describe mobility of screw dislocations in these materials. Studies of fundamental dislocation processes at atomic length scale are numerically and computationally intensive problems. This work studies the calculation of zero-stress formation energies of kink-pair configurations for BCC crystals. Our model for stored energy associated to a dislocation line configuration is based on the theory of discrete dislocations of Ariza and Ortiz. Its value is computed efficiently using an algorithm developed on the NVIDIA Compute Unified Device Architecture (CUDA). Results confirm those obtained using atomistic potentials and first principles calculations, and those based on the continuum theory of dislocations.
Abstract
Motion of screw dislocations in BCC materials at low temperature is believed to be related to the formation of mobile kinks on the dislocation line. Therefore, the accurate [...]
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Elementos finitos em formulação mista de mínimos quadrados para a simulação da convecção-difusão em regime transiente
V. Ruas, R. Leal-Toledo, M. Kischinhevsky

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)

Abstract
A mixed least-squares finite element scheme designed for solving the transient convection-diffusion equations expressed in terms of both the primal unknown and its flux, incorporating or not a reaction term, is studied. Once a time discretization of the Crank-Nicholson type is performed, the resulting system of equations allows for a stable approximation of both fields, by means of classical Lagrange continuous piecewise polynomial functions of arbitrary degree, in both simplicial and non-simplicial geometry, in any space dimension. The scheme is also convergent in space in the mean-square sense as far as the primal unknown field, its gradient, the flux variable and its divergence are concerned, and in time in an appropriate sense for each one of these four fields. Numerical results certify that the scheme performs well for any Péclet number, thereby allowing to confirm theoretical predictions, at least in the case where there is no narrow boundary layer. In the latter case however the method fails to produce reliable results. The technique is also compared with three existing methods to solve the convection-diffusion equations in the transient case. These include two recent ones proposed by the first author and collaborators.
Abstract
A mixed least-squares finite element scheme designed for solving the transient convection-diffusion equations expressed in terms of both the primal unknown and its flux, incorporating [...]
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Discrete neural compensator algorithm of dynamic in mobile robots using extended Kalman filter
F. Rossomando, C. Soria, R. Carelli

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)

Abstract
This paper presents the design of an algorithm based on neural networks in discrete time for its application in mobile robots. In addition, the system stability is analyzed and an evaluation of the experimental results is shown. The mobile robot has two controllers, one addressed for the kinematics and the other one designed for the dynamics. Both controllers are based on the feedback linearization. The controller of the dynamics only has information of the nominal dynamics (parameters). The neural algorithm of compensation adapts its behaviour to reduce the perturbations caused by the variations in the dynamics and the model uncertainties. Thus, the differences in the dynamics between the nominal model and the real one are learned by a neural network RBF (radial basis functions) where the output weights are set using the extended Kalman filter. The neural compensation algorithm is efficient, since the consumed processing time is lower than the one required to learning the totality of the dynamics. In addition, the proposed algorithm is robust with respect to failures of the dynamic controller. In this work, a stability analysis of the adaptable neural algorithm is shown and it is demonstrated that the control errors are bounded depending on the error of approximation of the neural network RBF. Finally, the results of experiments performed by using a mobile robot are shown to test the viability in practice and the performance for the control of robots.
Abstract
This paper presents the design of an algorithm based on neural networks in discrete time for its application in mobile robots. In addition, the system stability is analyzed [...]
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Application of an evolutionary algorithm for optimizing the computational modeling of materials pyrolysis
E. Puente, M. Lázaro, O. Abreu, J. Capote, D. Alvear

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
The pyrolysis models undergoes a fast development due to the enhancement of both the computational power and the new test used to characterize the behaviour of materials under thermal stresses, which were widely used in the field of the chemical engineering to obtain the reaction rates. Thus, these models allow us to characterize either the transient heat of material (thermal inertia) or the complete chemical scheme of mass loss processes (kinetic triplet). The pyrolysis model needs a several number of parameters what does the optimization of a suitable set of parameters a difficult task. Two kinds of materials have been investigated, the first one was a real material which mass loss process was characterized as “one-step” reaction and the second one as a “two-steps” process. Further, it has been analyzed the influence of some algorithm features (initial population number, parameter range, crossover influence) in the optimization time and also in the accuracy of results.
Abstract
The pyrolysis models undergoes a fast development due to the enhancement of both the computational power and the new test used to characterize the behaviour of materials under [...]
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A proper generalized decomposition strategy for dynamic data driven application systems
F. Masson, D. González, E. Cueto, F. Chinesta

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (2)

Abstract
Dynamic Data Driven Application Systems (DDDAS) appear as a new paradigm in the field of applied sciences and engineering, and in particular in simulation-based engineering sciences. By DDDAS we mean a set of techniques that allow the linkage of simulation tools with measurement devices for real-time control of systems and processes. DDDAS entails the ability to dynamically incorporate additional data into an executing application, and in reverse, the ability of an application to dynamically steer the measurement process. DDDAS needs for accurate and fast simulation tools making use if possible of off-line computations for limiting as possible the on-line computations. We could define efficient solvers by introducing all the sources of variability as extra-coordinates in order to solve off-line only once the model to obtain its most general solution to be then considered in on-line purposes. However, such models result defined in highly multidimensional spaces suffering the so-called curse of dimensionality. We proposed recently a technique, the Proper Generalized Decomposition (PGD), able to circumvent the redoubtable curse of dimensionality. The marriage of DDDAS concepts and tools and PGD off-line computations could open unimaginable possibilities in the field of dynamics data-driven application systems. In this work we explore some possibilities in the context of parameter estimation.
Abstract
Dynamic Data Driven Application Systems (DDDAS) appear as a new paradigm in the field of applied sciences and engineering, and in particular in simulation-based engineering [...]
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Efficient implementation of a semi-recursive formulation for the dynamics of large size multibody systems
A. Hidalgo, J. Jalón

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
This article shows an efficient implementation of a dynamic semi-recursive formulation for large and complex multibody system simulations, with interesting applications in the automotive field and especially with industrial vehicles. These systems tend to have a huge amount of kinematic constraints, becoming usual the presence of redundant but compatible systems of equations. The maths involved in the solution of these problems have a high computational cost, making very challenging to achieve real-time simulations. In this article, two implementations to increase the efficiency of these computations will be shown. The difference between them is the way they consider the Jacobian matrix of the constraint equations. The first one treats this matrix as a dense one, using the BLAS functions to solve the system of equations. The second one takes into account the sparse pattern of the Jacobian matrix, introducing the sparse function MA48 from Harwell. Both methodologies have been applied on two multibody system models with different sizes. The first model is a vehicle IVECO DAILY 35C15 with 17 degrees of freedom. The second one is a semi-trailer truck with 40 degrees of freedom. Taking as a reference the standard C/C + + implementation, the efficiency improvements that have been achieved using dense matrices (BLAS) have been of 15% and 50% respectively. The results in the first model have not improved significantly by using sparse matrices, but in the second one, the times with sparse matrices have been reduced 8% with respect to the BLAS ones.
Abstract
This article shows an efficient implementation of a dynamic semi-recursive formulation for large and complex multibody system simulations, with interesting applications in [...]
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A robust optimization hybrid algorithm for solving the direct kinematics of the general Gough-Stewart platform
E. Hernández-Martínez, S. Valdez-Peña, E. Sánchez-Soto

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
The direct kinematics problem for parallel robots can be stated as follows: given values of the joint variables, the corresponding Cartesian variable values, the pose of the end-effector, must be found. Most of the times the direct kinematics problem involves the solution of a system of non-linear equations. The most efficient methods to solve such kind of equations assume convexity in a cost function which minimum is the solution of the non-linear system. In consequence, the capacity of such methods depends on the knowledge about an starting point which neighboring region is convex, hence the method can find the global minimum. This article propose a method based on probabilistic learning about an adequate starting point for the Dogleg method which assumes local convexity of the function. The proposed method efficiently avoids the local minima, without need of human intervention or apriori knowledge, thus it shows a more robust performance than the simple Dogleg method or other gradient based methods. To demonstrate the performance of the proposed hybrid method, numerical experiments and the respective discussion are presented. The proposal can be extended to other structures of closed-kinematics chains, to the general solution of systems of non-linear equations, and to the minimization of non-linear functions.
Abstract
The direct kinematics problem for parallel robots can be stated as follows: given values of the joint variables, the corresponding Cartesian variable values, the pose of the [...]
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Solution on square domains of reaction-convection-diffusion equations using spectral stochastic finite element and streamline upwind Galerkin Petrov
D. Garzón-Alvarado, A. Ramírez-Martínez, C. Daza

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
In this paper we have developed the numerical solution of two problems of diffusion-convection (DC), using the finite element method of Streamline Upwind Petrov-Galerkin (SUPG). The parameters that define the behavior of the equations are modeled as stochastic fields, specifically, are used: the convective velocity, diffusion and heat capacity as values of random type. Therefore, we have included SUPG method to DC, with dominant convection, with the stochastic spectral finite element method. Each parameter was described by Karhunen-Loève expansion, while the unknown is represented by the polynomial expansion of the chaos. The objectives of the paper are: 1. To study the influence of stochastic fields in solving problems with SUPG DC and 2. Get the solution of each expansion unknown variable. The results show the versatility of the method for solving different physical problems due to the generality of the statistical description of the solution and the richness in the representation of the areas where there is the greater variability in response. The patterns shown in the unknown uncertainty depends on the dynamics of diffusion, convective velocity and the type of solution used.
Abstract
In this paper we have developed the numerical solution of two problems of diffusion-convection (DC), using the finite element method of Streamline Upwind Petrov-Galerkin (SUPG). [...]
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Developement of a computational tool for the analysis of reinforced concrete membrane elements
R. Souza

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)

Abstract
Reinforced concrete elements subjected to membrane forces, i.e., elements subjected to in-plane shear and axial stresses are very common for modeling complex structures such as aircraft hangars, nuclear power plants, offshore oil platforms and long-span bridges. While the design of reinforcement for membrane elements is well adressed the same can not be said regarding the analysis of performance of these elements. Into this context, the present paper aims at providing a numerical tool developed in the Matlab platform, taking into account the “Modified Compression Field Theory”. In order to certificate the performance of the proposed tool, extensive numerical results were compared with experimental results available in the literature. The obtained results revealed that the proposed tool is very confident for the analysis of reinforced concrete membrane elements.
Abstract
Reinforced concrete elements subjected to membrane forces, i.e., elements subjected to in-plane shear and axial stresses are very common for modeling complex structures such [...]
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A numerical model for the simulation of precipitates dissolution of hardened aluminium alloys using neural networks
C. Saracibar, R. López, B. Ducoeur, M. Chiumenti, B. Meester

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)

Abstract
The motivation of this work is the modeling of the hardening precipitate and hardness evolutions of fully hardened heat treatable aluminium alloys during friction stir welding (FSW) and/or heat treatment processes. The model used is based on the kinetics of dissolution of precipitates model for hardened aluminium alloys given by Myhr and Grong (1991). This model contains a single independent variable, the time, and a single state variable, the volume fraction of hardening precipitates. A key point of this model is the identification of the effective activation energy for precipitates dissolution and the master curve defining the model, which was given by a look-up table. The goal of this work is to find an estimation of the effective activation energy and to model the dissolution rate of hardening precipitate in aluminium alloys using neural networks, avoiding the use of look-up tables. For this purpose a new and more convenient parametrization of the master curve is defined, a neural networks class is proposed, an objective functional is defined and a variational problem including independent parameters is solved. The novel methodology has been applied to different aluminium alloys, including the AA 6005A T6, AA 7449 T79 and AA 2198 T8. Experimental tests have been carried out for those aluminium alloys in order to get the HV1 hardness after isothermal heat treatments at different temperatures and for different treatment time durations. The effective activation energy for hardening precipitates dissolution and the master curve of the model have been obtained, using different network architectures, for the aluminium alloys considered in this work.
Abstract
The motivation of this work is the modeling of the hardening precipitate and hardness evolutions of fully hardened heat treatable aluminium alloys during friction stir welding [...]
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Switching implicit-explicit numerical technique for nonlinear unstable structures
J. Curiel-Sosa, D. Owen

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (2)

Abstract
Simulation problems involving non-linear materials imply in numerous cases divergence of the implicit method which use return mapping algorithms for modelling of the nonlinear response. A switching implicit-explicit numerical technique in the context of Finite Element Methods is presented in this paper. Implicit/explicit mesh partitions are not considered whatsoever. Formulation for application to nonlinear hyperelastic materials and nonlinear elastic-plastic materials is provided. Furthermore, the response of the solid subjected to large deformations is presented and is embedded in the proposed technique. Numerical tests for nonlinear problems (geometric and/or material) showed the accurateness of the technique.
Abstract
Simulation problems involving non-linear materials imply in numerous cases divergence of the implicit method which use return mapping algorithms for modelling of the nonlinear [...]
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Steel compression design: the bucklings weigth
J. Cervera, J. Ortiz, M. Vázquez, A. Aznar

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (2)

Abstract
The verification of the slender compressed members of a structure is a well formulated and codified problem. However, the non-linearity of the design process, combined with the no linearity of the physical problem requires an iterative process to define the piece that solves a given problem. This paper demonstrates an identity relationship between seemingly different problems, based on which we develop a theoretical approach and a simple procedure to determine, without iteration and with little margin for error, the piece needed for a given problem. The paper provides a statistical model to check that the provided procedure is safe and effective in the 98% of the problems in buildings —pillars and bars from trusses—. The presented approach therefore greatly facilitates decisions in this area.
Abstract
The verification of the slender compressed members of a structure is a well formulated and codified problem. However, the non-linearity of the design process, combined with [...]
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An extension of Nelder-Mead method to nonlinear mixed-integer optimization problems
E. Brea

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (3)

Abstract
This article presents a new algorithm based on the Nelder-Mead simplex algorithmic method for identifying a local optimum, at least on unconstrained nonlinear mixed-integer problems. The algorithmic method, Integer Mixed Simplex Algorithm (IMSA), so called by the author, is based on a double simplex structure, which is composed of a real n -dimensional simplex structure (real simplex) and an integer n -dimensional simplex structure (integer simplex). The original Nelder-Mead operations are applied on the real simplex. Meanwhile, a novel group of operations are applied on the integer simplex. This new set of operations, together with the original Nelder-Mead operations, guarantee a new trail point at each IMSA iteration in the search of the local optimum in the integer real mixed 2n -dimensional numerical field ℝn×ℤn without the need of integer to real conversions.
Abstract
This article presents a new algorithm based on the Nelder-Mead simplex algorithmic method for identifying a local optimum, at least on unconstrained nonlinear mixed-integer [...]
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Posibilidades de un modelo sustituto de incendios mediante el empleo de redes neuronales
D. Lázaro, E. Puente, M. Lázaro, J. Capote, D. Alvear

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (3)

Abstract
In recent years there has been extensive development of the fire computer models, and its use in the study of the fire safety, fire investigation, etc. has been increased. The most important types of fire computer models are the field model and the zone model. The first model reaches a better approximation to fire dynamics, but the second one requires less computational time. Additionally, in the last years, it should be noted the great advances in information processing using artificial neural networks, and it has become a useful tool with application in very diverse fields. This paper analyzes the possibilities of develop a new fire computer model using artificial neural networks. In the first approach to this objective, a simple compartment was analyzed with a field model. After that, simulations employing General Regression Neural Network were performed. This method achieves similar results that the field model employing computational times closer to the zone models. The neural network has been trained with FDS field model and validating the resulting model with data from a full scale test. In later stages other phenomena and different types of networks will be evaluated.
Abstract
In recent years there has been extensive development of the fire computer models, and its use in the study of the fire safety, fire investigation, etc. has been increased. [...]
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Numerical study of efficiencies for box type solar cooker with internal reflectors
H. Terres-Peña, J. Morales-Gómez, A. Lizardi-Ramos, R. López-Callejas, R. Portillo-Vélez

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (2)

Abstract
In this work, results of efficiencies for first and second law of thermodynamics applied to four box-type solar cookers with internal reflectors are shown. The solar cooker has two glasses on its cover to diminish the losses of heat for radiation and convection, besides creating the effect hothouse inside the cooker. The interior of the cooker has flat mirrors placed at different angles to reflect the solar radiation toward a recipient with water inside the cooker. The obtained results are based on heating water temperatures which were obtained by means of numeric simulation, allowing comparison under identical conditions of four solar cookers. The treatment of the results revealed that the quantity of energy that impacts on the solar cookers is not used in right way for the heating water ends. Most of the profitable energy is stored in the glasses of the cover, what evidences the necessity to work in the development of better materials to diminish such situation.
Abstract
In this work, results of efficiencies for first and second law of thermodynamics applied to four box-type solar cookers with internal reflectors are shown. The solar cooker [...]
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Probabilistic assessment of the capacity, fragility and seismic damage of reinforced concrete buildings
Y. Vargas, L. Pujades, A. Barbat, J. Hurtado

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (2)

Abstract
Currently, many structures existing in seismic areas are highly vulnerable because they have been built without the use of seismic design codes or by using outdated codes. Often, methods for assessing the vulnerability of the structures do not take into account that their seismic behavior is dynamic and highly nonlinear and, moreover, that the structural characteristics and action have large uncertainties. This article aims to assess the vulnerability of structures taking into account that the mechanical properties of materials and the seismic action are random variables, by using advanced techniques based on the Monte Carlo method and on the nonlinear stochastic dynamics. The results obtained with these techniques are compared with those corresponding to a standard vulnerability assessment, based on deterministic models, in order to highlight the differences between both approaches. The main conclusion of this work is the need to address the vulnerability assessment problem from a probabilistic perspective which, combined with advanced nonlinear static and dynamic structural analysis techniques, provides a powerful tool giving information impossible to be captured by means of deterministic models. Finally, detailed results obtained for a building with waffle slabs, which is a structural typology widely used in Spain, are included and discussed.
Abstract
Currently, many structures existing in seismic areas are highly vulnerable because they have been built without the use of seismic design codes or by using outdated codes. [...]
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Application of the level set method to model the premixed combustion process in an otto two stroke engine
M. Galdo, C. Vidal, J. García

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
In this paper, the numerical method level set has been used to model the combustion process in an Otto two-stroke engine. The level set has been implemented in a CFD (Computational Fluid Dynamics) software based in finite volumes. The pressure and temperature fields have been obtained, such as the propagation of the flame front. In order to validate this model, the numerically obtained results have been compared with experimental data, verifying a satisfactory concordance between both of them. Besides, the level set method has been compared with other numerical procedure, showing the difference between both results.
Abstract
In this paper, the numerical method level set has been used to model the combustion process in an Otto two-stroke engine. The level set has been implemented in a CFD (Computational [...]
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On computing distance function for Level Set Method using USFEM/Rothe as stabilized formulation
C. H., A. Coutinho

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
In this work we use the Unusual Stabilized Finite Element Method (USFEM) associated to Rothes method for solving the redistancing problem in the Level Set Method . Rothes method is used first for advancing the solution in (pseudo)time and USFEM for solving the resulting steady advective–reaction problem in each time step. Several 2D problems are solved and results compared with SUPG scheme supplemented with a nonlinear discontinuity–capturing operator.
Abstract
In this work we use the Unusual Stabilized Finite Element Method (USFEM) associated to Rothes method for solving the redistancing problem in the Level Set Method . Rothes [...]
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An anisotropic diffusion model for the study of the urban traffic
V. Cortínez, P. Domínguez

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)

Abstract
In order to design or redesign urban transportation networks, the employment of mathematical models is very useful for predicting the effects of possible modifications of implementing. Such models allow the determination of vehicular flows and travel times for every link of the network from the knowledge of its inherent features and the corresponding traffic demand. They are based on a phenomenological law of the social collective behavior of the drivers called Wardrop principle. It is an optimization problem, in general, very demanding from the computational point of view. In order to accelerate the computation process, in this paper, a continuum model for the urban traffic is proposed. The fundamental assumption behind this theory is that the variation of network properties is small in close regions when compared with the full system. Accordingly, it is possible to use continuous functions for representing travel times or vehicular flows. Essentially, the problem is formulated as a system of non-linear anisotropic diffusion (differential) equations that can be conveniently solved by means of the finite element method. The efficiency of the proposed model is studied by means of a comparison with results obtained with the classical optimization approach. As shown, the results are similar although the computation times are significantly reduced.
Abstract
In order to design or redesign urban transportation networks, the employment of mathematical models is very useful for predicting the effects of possible modifications of [...]
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Numerical model of the hysteretic behavior of connections between waffle slabs and façade supports
X. Cahís, A. Benavent-Climent, A. Goñi

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
Waffle-flat-plate structures have been widely used for residential and office buildings in the South of Europe between the seventies and nineties of the last century. These buildings were designed with old seismic codes and its vulnerability needs to be evaluated to determine whether they need to be seismic retrofitted or not. This article proposes a simple model that represents the moment transfer between plate and column, for existing exterior connections loaded in the direction normal to the building façade. The model takes into account singularities of existing waffle-flat-plate structures such as the concentration of reinforcement in the direction of the joints, and the existence of punching shear reinforcement. The model consists of frame elements for the columns and shell elements for the slabs, both connected with flexural and torsion hinges. The strength of the flexural hinges is obtained by estimating the portion of longitudinal reinforcement of the plate that transfers directly the unbalanced moment to the column by flexure. The yielding deformations of the flexural and torsion hinges are estimated with simple expressions. The ductility of the flexural hinges is taken from FEMA 356, while infinite ductility is adopted for the torsional hinges in accordance with previous experimental studies. It is shown that the proposed model provides a good approximation of the experimental response of the connection under monotonically increasing lateral displacements, in terms of stiffness, strength and ductility.
Abstract
Waffle-flat-plate structures have been widely used for residential and office buildings in the South of Europe between the seventies and nineties of the last century. These [...]
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Algorithm for defining skeletal structures in biomedical models
D. Ortega, G. Gutiérrez, A. Iznaga, T. Rodríguez, M. Beule, B. Verhegghe

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
Description of mechanical behavior of hard tissues by means of discrete models goes through various stages of analysis, which range from digital image processing to the specification of physical properties of tissue to the discrete model. This requires taking into account a key element: the decomposition of the model into its constituent parts. We conducted a bibliographic study of existing proposals for such decomposition, leading to the conclusion of the absence of a single strategy. There are several generic proposals, but these proved not to give a valid solution applicable to the cases examined corresponding to the articulations of the knee, hip and shoulder. In this paper we propose an algorithm to perform this decomposition by analyzing the spatial relationships between the contours present in consecutive planes. It is based on four stages: reading computer tomography (CT) slices, determining the contours that define bone tissue present on each slice, grouping of contours whose relationship meets a given criterion, and eliminating non-valid volumes. Results were compared with those obtained by means of Visualization ToolKit (VTK) and pyFormex, widely used in the visualization and analysis of medical imaging and modeling three-dimensional structures. As a main result, proposed algorithm under the same conditions and short processing time performs a better decomposition of anatomical models than the one made by VTK and pyFormex, with about a 90% of confidence.
Abstract
Description of mechanical behavior of hard tissues by means of discrete models goes through various stages of analysis, which range from digital image processing to the specification [...]
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Numerical modeling of the thermal discharge of the Laguna Verde power station
H. Ramírez-León, C. Couder-Castañeda, I. Herrera-Díaz, H. Barrios-Piña

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (2)

Abstract
This work contributes to the study of nuclear plant thermal discharges in coastal areas by using a numerical model which solves the Navier-Stokes-Reynolds equations for shallow waters and the energy equation for computing temperature variations. The numerical model takes into account the heat flux given in the upper layer, where the free surface and the atmosphere interact. In this study, the thermal plume dispersion from the nuclear power plant Laguna Verde, Veracruz, Mexico, is analyzed. Bathymetry, oceanographic, meteorological, hydrologic and plant operating data are used to run numerical simulations. The results are compared against observed data showing good agreement. The Nash-Suffles criterion is also applied to verify the quality of the numerical solution obtaining suitable results.
Abstract
This work contributes to the study of nuclear plant thermal discharges in coastal areas by using a numerical model which solves the Navier-Stokes-Reynolds equations for shallow [...]
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Numerical modeling to study fluid-solid interfaces under dynamic excitations
E. Flores-Méndez, M. Carbajal-Romero, N. Flores-Guzmán, J. Núñez-Farfán

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (3)

Abstract
This work shows the wave propagation in fluid-solid interfaces due to dynamic excitations, such interface waves are known as Scholtes waves. We studied a wide range of elastic solid materials used in engineering. The interface connects an acoustic medium (fluid) and another solid. It has been shown that by means of an analysis of diffracted waves in a fluid, it is possible to deduce the mechanical characteristics of the solid medium, specifically, its propagation velocities. For this purpose, the diffracted field of pressures and displacements, due to an initial pressure in the fluid, are expressed using boundary integral representations, which satisfy the equation of motion. The initial pressure in the fluid is represented by a Hankels function of second kind and zero order. The solution to this problem of wave propagation is obtained by means of the Indirect Boundary Element Method, which is equivalent to the well-known Somiglianas representation theorem. The validation of the results was performed by means of the Discrete Wave Number Method. Firstly, spectra of pressures to illustrate the behavior of the fluid for each solid material considered are included, then, the Fast Fourier Transform algorithm to display the results in the time domain is applied, where the emergence of Scholtes waves and the amount of energy that they carry are highlighted.
Abstract
This work shows the wave propagation in fluid-solid interfaces due to dynamic excitations, such interface waves are known as Scholtes waves. We studied a wide range of elastic [...]
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Model of a continuous crystallization process for a sorbet by the moments methodology
J. Ramírez, D. Leducq, M. Arellano, G. Álvarez

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (4)

Abstract
Freezing is an important step in the manufacturing process of ice-cream and sorbet, since the operating conditions have a strong influence on the micro-structure, and consequently on the sensorial attributes of the final product. This steep of freezing is carried out by a scraped surface heat exchanger (SSHE) where the product quality is conditioned by process conditions as the evaporation temperature of a refrigerant fluid, the mix flow rate, the dasher speed and the cylinder pressure due to the air introduction. In order to study the relevance of a control system based on the influence of process variables on product quality, this paper presents a model for a continuous crystallization of a sorbet using the method of moments, which is validated by experimental data.The model created by this methodology has been able to represent the influence of the process conditions during the crystallization of the sorbet on the final product characteristics such as crystal size and the draw temperature in the outlet of the SSHE in absence of air. The model based in moments is studied as a reduced model of the population balance equation and includes the phenomena of heterogeneous nucleation and growth. This model developed represents minimal computational requirements and is highly adapted for optimization and/or process control tasks.
Abstract
Freezing is an important step in the manufacturing process of ice-cream and sorbet, since the operating conditions have a strong influence on the micro-structure, and consequently [...]
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Erratum to “Comparative study of models of impedance boundary conditions in acoustic problems”
A. Garriga, C. Spa, L. Pozo

Rev. int. métodos numér. cálc. diseño ing. (2013). Vol. 29, (1)
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Research lines and software products for the oil and gas industry
. Informe

(2008). Technical Report, IT547
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A contribution to the Finite Element Analysis of High-Speed compressible flows and aerodynamic shape optimization
M. Kouhi, E. Oñate, G. Bugeda

Monograph CIMNE (2013). M140

Abstract
This work covers a contribution to two most interesting research fields in aerodynamics, the finite element analysis of high-speed compressible flows (Part I) and aerodynamic shape optimization (Part II).The first part of this study aims at the development of a new stabilization formulation based on the Finite Increment Calculus (FIC) scheme for the Euler and Navier-Stokes equations in the context of the Galerkin finite element method (FEM). The FIC method is based on expressing the balance of fluxes in a space-time domain of finite size. It is tried to prevent the creation of instabilities normally presented in the numerical solutions due to the high convective term and sharp gradients.In order to overcome the typical instabilities happening in the numerical solution of the high-speed compressible flows, two stabilization terms, called streamline term and transverse term, are added through the FIC formulation in space-time domain to the original conservative equations of mass, momentum and energy. Generally, the streamline term holding the direction of the velocity is responsible for stabilizing the spurious solutions produced from the convective term while the transverse term smooths the solution in the high gradient zones. An explicit fourth order Runge-Kutta scheme is implemented to advance the solution in time.In order to investigate the capability of the proposed formulation, some numerical test examples corresponding to subsonic, transonic and supersonic regimes for inviscid and viscous flows are presented. The behavior of the proposed stabilization technique in providing appropriate solutions has been studied especially near the zones where the solution has some complexities such as shock waves, boundary layer, stagnation point, etc. Although the derived methodology delivers precise results with a nearly coarse mesh, the mesh refinement technique is coupled in the solution to create a suitable mesh particularly in the high gradient zones.The comparison of the numerical results obtained from the FIC formulation with the reference ones demonstrates the robustness of the proposed method for stabilization of the Euler and Navier-Stokes equations. It is observed that the usual oscillations occur in the Galerkin FEM, especially near the high gradient zones, are cured by implementing the proposed stabilization terms. Furthermore, allowing the adaptation framework to modify the mesh, the quality of the results improves significantly.The second part of this thesis proposes a procedure for aerodynamic shape optimization combining Genetic Algorithm (GA) and mesh refinement technique. In particular, it is investigated the effect of mesh refinement on the computational cost and solution accuracy during the process of aerodynamic shape optimization. Therefore, an adaptive remeshing technique is joined to the CFD solver for the analysis of each design candidate to guarantee the production of more realistic solutions during the optimum design process in the presence of shock waves.In this study, some practical transonic airfoil design problems using adaptive mesh techniques coupled to Multi-Objective Genetic Algorithms (MOGAs) and Euler flow analyzer are addressed. The methodology is implemented to solve three practical design problems; the first test case considers a reconstruction design optimization that minimizes the pressure error between a predefined pressure curve and candidate pressure distribution. The second test considers the total drag minimization by designing airfoil shape operating at transonic speeds. For the final test case, a multi-objective design optimization is conducted to maximize both the lift to drag ratio (L/D) and lift coefficient (Cl). The solutions obtained with and without adaptive mesh refinement are compared in terms of solution accuracy and computational cost. These design problems under transonic speeds need to be solved with a fine mesh, particularly near the object, to capture the shock waves that will cost high computational time and require solution accuracy.By comparison of the the numerical results obtained with both optimization problems, the obtainment of direct benefits in the reduction of the total computational cost through a better convergence to the final solution is evaluated. Indeed, the improvement of the solution quality when an adaptive remeshing technique is coupled with the optimum design strategy can be judged.
Abstract
This work covers a contribution to two most interesting research fields in aerodynamics, the finite element analysis of high-speed compressible flows (Part I) and aerodynamic [...]
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El papel de los modelos numéricos en la investigación y el diseño de aliviaderos de presas
F. Salazar, J. Mauro, J. Irazábal, A. Larese, . R. Rossi, E. Oñate, R. Morán, M. Toledo

(2013). Research Report, Nº PI396

Abstract
El Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE) es un centro de investigación dependiente del Gobierno de Cataluña y de la Universidad Politécnica de Cataluña creado en 1987. Su principal actividad es el desarrollo y aplicación de métodos numéricos innovadores para resolver problemas prácticos en diversos campos de la ingeniería, y se desarrolla fundamentalmente en el marco de proyectos de investigación nacionales e internacionales. En los últimos años el centro ha participado en diversos proyectos relacionados con la seguridad de presas, fundamentalmente hidráulica, pero también estructural, en cooperación con diversas empresas y organismos públicos de investigación como el CEDEX y la UPM. La presente comunicación describe brevemente los objetivos principales de los mencionados proyectos, haciendo hincapié en cómo la modelación numérica ha contribuido a alcanzarlos.
Abstract
El Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE) es un centro de investigación dependiente del Gobierno de Cataluña y [...]
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