Analysis of columns with sheardeformation using finite element method and equivalent distributedloads

En este trabajo se aplica un procedimiento basado en el concepto de Acción Repartida Equivalente (ARE) al análisis, por el Método de Elementos Finitos (MEF) formulado en desplazamientos y solución nodal exacta, de pilares con deformación por cortante de acuerdo con la teoría de Timoshenko. Los resultados obtenidos con la metodología ARE-MEF, en los casos analizados, ponen de manifiesto que con un número muy reducido de elementos (uno y dos en los ejemplos desarrollados) se alcanza gran exactitud en desplazamientos, giros y esfuerzos. Sin embargo con otras metodologías formuladas en desplazamientos, como por ejemplo la de integración reducida, se requiere del orden de 40 elementos para alcanzar resultados similares. Asimismo en el presente trabajo, a partir del MEF con solución nodal exacta se determinan de una forma directa y sistemática las funciones de estabilidad y la carga de pandeo para el pilar de Timoshenko.This paper describes a procedure based on the concept of Equivalent Distributed Loads (EDL) applied to the Finite Elements Method (FEM) based on displacements and exact nodal solution of columns subject to shear deformation in accordance with the Timoshenko beam theory. The results obtained using this “EDL-FEM” methodology, in the cases studied, show that a high level of exactness in displacements, rotations as well as shear force and bending moment is obtained with a very small number of elements (one or two in the examples developed). Other methodologies based on displacements, such as reduced integration, require on the order of 40 elements to achieve similar results. The stability functions and buckling load for the Timoshenko beam are also determined in a direct and systematic way from the FEM with exact nodal solution.Peer Reviewe

Comportamiento de elementos estructurales de compuestos híbridos base cemento frente a impacto de torre de caída

The performance, under drop-weight impact load, of hybrid cement composite (HCC) elements, consisting of a top layer of plain concrete (PC) and a bottom layer of fibre reinforced concrete (FRC), in comparison with full-depth FRC and PC was studied. Apart from improving the tensile capacity of PC and saving fibre steel reinforcements of FRC, the results showed that HCC can effectively control the deformations and enhance the impact performance of the structural members as its outcomes were similar to that of a full-depth FRC. The analytical studies using Hughes empirical formulae (HEF) and yield line theory (YLT) adopted to investigate the practical use of HCC showed that they are applicable for design such HCC elements against impacts.Se estudió el comportamiento, frente a impacto de torre de caída, de elementos híbridos base cemento (HCC), formados por una capa superior de hormigón en masa (PC) y una capa inferior de hormigón reforzado con fibras (FRC) en comparación con elementos análogos íntegramente fabricados con FRC y PC. Además de proporcionar una mejora en la resistencia frente a flexo-tracción de los PC y un ahorro en refuerzo usando fibras de acero en el caso de los FRC, los resultados mostraron que el HCC puede controlar eficazmente las deformaciones y mejorar el rendimiento frente a impacto de los elementos estructurales ya que sus resultados fueron análogos a la de los FRC. Los estudios analíticos, utilizando HEF e YLT, adoptados para investigar el uso práctico de los HCC mostraron que los mismos son aplicables para el diseño de estos elementos frente a impacto

Análisis de la relevancia de las revistas latinoamericanas a través de un factor de impacto renormalizado

In this work we use a renormalized impact factor to analyze the time evolution of Latin American scientific journals from 1991 to 2000. Our analysis shows oscillant behavior in journals’ relevance in the international context in the last years.<br><br>En este trabajo usamos el factor de impacto renormalizado para obtener la evolución temporal de un indicador de relevancia de las revistas científicas latinoamericanas en el periodo de 1991 a 2000. Nuestro análisis muestra un comportamiento oscilante en la relevancia en el contexto internacional en los últimos años

Evaluación estructural de los efectos climáticos en la cubierta de mampostería no reforzada del invernadero del IETcc proyectada por E. Torroja

In this paper, the design and causes of deterioration of the Winter Garden located in the Eduardo Torroja Institute for Construction Sciences (IETcc) in Madrid, as well as the structural rehabilitation works carried out are discussed. The structural and architectural scheme was devised by E. Torroja and is examined using numerical analysis under dead load. This allows the failure pattern of the arches and shells to be assessed, as a consequence of water ingress through the cracks formed and settlement, as also the effectiveness of the repair techniques applied in 2009.En este trabajo, se discuten el diseño y las causas de deterioro del edificio del invierno situado en el Instituto de Ciencias de la Construcción Eduardo Torroja (IETcc) en Madrid, así como las obras de rehabilitación de mantenimiento de la estructura ejecutadas. El esquema estructural y arquitectónico ideado por E. Torroja se examinó utilizando análisis numérico considerando el efecto de la carga muerta. Esto permite analizar el tipo de fallo observado en los arcos y la cubierta abovedada, como consecuencia del asentamiento y de la entrada de agua a través de las fisuras formadas así como la eficacia de las técnicas de reparación realizadas en 2009

SWE bridge: software interface for plug & work instrument integration into marine observation platforms

7th International Workshop on Marine Technology – Martech Workshop 2016, 26-28 October 2016, Barcelona.-- 2 pages, 2 figuresThe integration of sensor systems into marine observation platforms such as gliders, cabled observatories and smart buoys requires a great deal of effort due to the diversity of architectures present in the marine acquisition systems. In the past years important steps have been taken in order to improve both standardization and interoperability, i.e. the Open Geospatial Consortium’s Sensor Web Enablement. This set of standards and protocols provide a well-defined framework to achieve standardized data chains. However a significant gap is still present in the lower-end of the data chain, between the sensor systems and the acquisition platforms. In this work a standards-based architecture to bridge this gap is proposed in order to achieve plug & work, standardized and interoperable acquisition systemsWe acknowledge the financial support from Spanish Ministerio de Economía y Competitividad under contract CGL2013- 42557-R INTMARSIS, the European Union’s NeXOS Project under contract nº 614102 and EMSODEV Project under contract n°676555Peer Reviewe

Deconvolution problems in x-ray absorption fine structure

A Bayesian method application to the deconvolution of EXAFS spectra is considered. It is shown that for purposes of EXAFS spectroscopy, from the infinitely large number of Bayesian solutions it is possible to determine an optimal range of solutions, any one from which is appropriate. Since this removes the requirement for the uniqueness of solution, it becomes possible to exclude the instrumental broadening and the lifetime broadening from EXAFS spectra. In addition, we propose several approaches to the determination of optimal Bayesian regularization parameter. The Bayesian deconvolution is compared with the deconvolution which uses the Fourier transform and optimal Wiener filtering. It is shown that XPS spectra could be in principle used for extraction of a one-electron absorptance. The amplitude correction factors obtained after deconvolution are considered and discussed.Comment: 6 two-column pages, 5 eps figures; submitted to J. Phys.: Appl. Phy

Realización de un grafo en recintos rectangulares sobre una planta definida

In this paper, the problem of mapping a graph into a set of rectangles covering a given plan is analyzed. The plan must have its sides parallel to two perpendicular directions. The graph may represent the basic scheme of a housing or a building, in which the different design requirements are collected. To this aim, the problem of partitioning a rectangle into rectangles is analyzed. It consists in determining whether a given graph can be realized this way, and if so, automatically generate some of its realizations. A general method is proposed to solve both aspects of the problem. It is a problem with practical application in areas such as architectural design or compaction of electronic circuits, to which no general solution has been found in the specialized bibliography.En este trabajo se analiza el problema de la realización de un grafo en un conjunto de recintos rectangulares que cubran una planta dada, de lados paralelos a dos direcciones perpendiculares. Los grafos pueden representar el esquema básico de una vivienda o de un edificio y en él se muestran distintos requerimientos del proyecto. Para ello, se analiza el problema de la partición de un rectángulo en rectángulos, esto es, dado un grafo, saber si admite una realización de esta clase y, en caso afirmativo, generar automáticamente dichas realizaciones. En ambos aspectos, se propone un procedimiento completo y general. Se trata de un problema de aplicación práctica en áreas tales como proyecto arquitectónico o compactación de circuitos electrónicos, del que no se ha encontrado una solución general en la bibliografía consultada

Thin film growth and band lineup of In2O3 on the layered semiconductor InSe

Thin films of the transparent conducting oxide In2O3 have been prepared in ultrahigh vacuum by reactive evaporation of indium. X-ray diffraction, optical, and electrical measurements were used to characterize properties of films deposited on transparent insulating mica substrates under variation of the oxygen pressure. Photoelectron spectroscopy was used to investigate in situ the interface formation between In2O3 and the layered semiconductor InSe. For thick In2O3 films a work function of φ = 4.3 eV and a surface Fermi level position of EF−EV = 3.0 eV is determined, giving an ionization potential IP = 7.3 eV and an electron affinity χ = 3.7 eV. The interface exhibits a type I band alignment with ΔEV = 2.05 eV, ΔEC = 0.29 eV, and an interface dipole of δ = −0.55 [email protected]

First principles determination of some static and dynamic properties of the liquid 3d transition metals near melting

Producción CientíficaWe report an ab initio molecular dynamics simulation study of several static and dynamic properties of the liquid 3d transition metals. The calculated static structure factors show qualitative agreement with the available experimental data, and its second peak displays an asymmetric shape which suggests a signi1cant local icosahedral short-range order. The dynamical structure reveals propagating density 2uctuations whose dispersión relation has been evaluated; moreover, its long wavelength limit is compatible with their respective experimental sound velocity. Results are reported for the longitudinal and transverse current spectral functions as well as for the respective dispersion relations. We also analyze the possible appearance of transverse-like low-energy excitations in the calculated dynamic structure factors. Several transport coeWcients have been evaluated and compared with the available experimental data.Junta de Castilla y León (Ref. project VA124G18)Ministerio de Economía, Industria y Competitividad (Project PGC2018-093745-B-I00) and FEDE