157 research outputs found
An overview of research on gender in Spanish society
No full textThis article presents an overview of research on gender in Spanish society. Six areas of literature are examined including families, education, work, politics, sexuality, and men. The author argues that political factors have shaped the development of sociology of gender in Spain and that there are still important gaps in coverage in this area of sociological inquiry.Publicad
El feminismo de Estado en España: El Instituto de la Mujer (1983-2003)
No full textDesde aproximadamente los años setenta se han fundado en la mayor parte de los países del mundo instituciones cuyo principal cometido reside en mejorar la condición de las mujeres como grupo y erosionar las desigualdades entre éstas y los hombres. También se han establecido organismos similares en los ámbitos regional y local. En ciencias sociales este conjunto de instituciones se denomina "feminismo de Estado", "feminismo institucional" o "feminismo oficial", conociéndose como "feministas de Estado" a las personas que trabajan en estos "organismos (o agencias) de igualdad" o "instituciones feministas" (McBride y Mazur 2004, 2; Stetson y Mazur 1995, 1-2).
3D analysis of the influence of specimen dimensions on fretting stresses
No full text[EN] In this paper, the contact conditions and stresses that arise in a fretting test have been analyzed by means of a three-dimensional finite element model of the contact between a sphere and a flat surface. An h-adaptive process, based on element subdivision, has been used in order to obtain a low discretization error at a reasonable computational cost. The influence of finite dimensions of the specimen in the stress fields has been evaluated. The results have been compared with the classical Cattaneo-Mindlin solution.The authors wish to thank the financial support received from CICYT by means of the project PB97-0696-C02-02.Tur Valiente, M.; Fuenmayor Fernández, F.; J.J. Ródenas; Giner Maravilla, E. (2003). 3D analysis of the influence of specimen dimensions on fretting stresses. Finite Elements in Analysis and Design. 39(10):933-949. https://doi.org/10.1016/S0168-874X(02)00139-7S933949391
Superconvergent patch recovery with constraints for three‐dimensional contact problems within the Cartesian grid Finite Element Method
No full text"This is the peer reviewed version of the following article: Navarro-Jiménez, José M., Héctor Navarro-García, Manuel Tur, and Juan J. Ródenas. 2019. Superconvergent Patch Recovery with Constraints for Three-dimensional Contact Problems within the Cartesian Grid Finite Element Method. International Journal for Numerical Methods in Engineering 121 (6). Wiley: 1297 1313. doi:10.1002/nme.6266, which has been published in final form at https://doi.org/10.1002/nme.6266. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The superconvergent patch recovery technique with constraints (SPR-C) consists in improving the accuracy of the recovered stresses obtained with the original SPR technique by considering known information about the exact solution, like the internal equilibrium equation, the compatibility equation or the Neumann boundary conditions, during the recovery process. In this paper the SPR-C is extended to consider the equilibrium around the contact area when solving contact problems with the Cartesian grid Finite Element Method. In the proposed method, the Finite Element stress fields of both bodies in contact are considered during the recovery process and the equilibrium is enforced by means of the continuity of tractions along the contact surface.The authors would like to thank Generalitat Valenciana (PROMETEO/2016/007), the Spanish Ministerio de Economía, Industria y Competitividad (DPI2017-89816-R), the Spanish Ministerio de Ciencia, Innovación y Universidades (FPU17/03993), and Universitat Politècnica de València (FPI2015) for the financial support to this work.Navarro-Jiménez, J.; Navarro-García, H.; Tur Valiente, M.; Ródenas, JJ. (2020). Superconvergent patch recovery with constraints for three-dimensional contact problems within the Cartesian grid Finite Element Method. International Journal for Numerical Methods in Engineering. 121(6):1297-1313. https://doi.org/10.1002/nme.6266S129713131216Wriggers, P. (2006). Computational Contact Mechanics. doi:10.1007/978-3-540-32609-0Marco, O., Sevilla, R., Zhang, Y., Ródenas, J. J., & Tur, M. (2015). Exact 3D boundary representation in finite element analysis based on Cartesian grids independent of the geometry. International Journal for Numerical Methods in Engineering, 103(6), 445-468. doi:10.1002/nme.4914Navarro-Jiménez, J. M., Tur, M., Albelda, J., & Ródenas, J. J. (2018). Large deformation frictional contact analysis with immersed boundary method. Computational Mechanics, 62(4), 853-870. doi:10.1007/s00466-017-1533-xMarco, O., Ródenas, J. J., Navarro-Jiménez, J. M., & Tur, M. (2017). Robust h-adaptive meshing strategy considering exact arbitrary CAD geometries in a Cartesian grid framework. Computers & Structures, 193, 87-109. doi:10.1016/j.compstruc.2017.08.004Ródenas, J. J., Tur, M., Fuenmayor, F. J., & Vercher, A. (2007). Improvement of the superconvergent patch recovery technique by the use of constraint equations: the SPR-C technique. International Journal for Numerical Methods in Engineering, 70(6), 705-727. doi:10.1002/nme.1903Zienkiewicz, O. C., & Zhu, J. Z. (1992). The superconvergent patch recovery (SPR) and adaptive finite element refinement. Computer Methods in Applied Mechanics and Engineering, 101(1-3), 207-224. doi:10.1016/0045-7825(92)90023-dRódenas, J. J., González-Estrada, O. A., Díez, P., & Fuenmayor, F. J. (2010). Accurate recovery-based upper error bounds for the extended finite element framework. Computer Methods in Applied Mechanics and Engineering, 199(37-40), 2607-2621. doi:10.1016/j.cma.2010.04.010Blacker, T., & Belytschko, T. (1994). Superconvergent patch recovery with equilibrium and conjoint interpolant enhancements. International Journal for Numerical Methods in Engineering, 37(3), 517-536. doi:10.1002/nme.1620370309Díez, P., José Ródenas, J., & Zienkiewicz, O. C. (2007). Equilibrated patch recovery error estimates: simple and accurate upper bounds of the error. International Journal for Numerical Methods in Engineering, 69(10), 2075-2098. doi:10.1002/nme.1837Nadal, E., Díez, P., Ródenas, J. J., Tur, M., & Fuenmayor, F. J. (2015). A recovery-explicit error estimator in energy norm for linear elasticity. Computer Methods in Applied Mechanics and Engineering, 287, 172-190. doi:10.1016/j.cma.2015.01.013Badia, S., Verdugo, F., & Martín, A. F. (2018). The aggregated unfitted finite element method for elliptic problems. Computer Methods in Applied Mechanics and Engineering, 336, 533-553. doi:10.1016/j.cma.2018.03.022Zienkiewicz, O. C., Zhu, J. Z., & Wu, J. (1993). Superconvergent patch recovery techniques - some further tests. Communications in Numerical Methods in Engineering, 9(3), 251-258. doi:10.1002/cnm.1640090309FUENMAYOR, F. J., & OLIVER, J. L. (1996). CRITERIA TO ACHIEVE NEARLY OPTIMAL MESHES IN THEh-ADAPTIVE FINITE ELEMENT METHOD. International Journal for Numerical Methods in Engineering, 39(23), 4039-4061. doi:10.1002/(sici)1097-0207(19961215)39:233.0.co;2-cBabuška, I., Strouboulis, T., & Upadhyay, C. . (1994). A model study of the quality of a posteriori error estimators for linear elliptic problems. Error estimation in the interior of patchwise uniform grids of triangles. Computer Methods in Applied Mechanics and Engineering, 114(3-4), 307-378. doi:10.1016/0045-7825(94)90177-
Stabilized method of imposing Dirichlet boundary conditions using a recovered stress field
No full text[EN] This paper proposes a new formulation to impose Dirichlet boundary conditions on immersed boundary Cartesian Finite Element meshes. The method uses a recovered stress field calculated by Superconvergent Patch Recovery to stabilize the Lagrange multiplier formulation of the problem. The optimal convergence of the method and the convergence of the proposed iterative procedure are demonstrated. The proposed method is also suitable for problems with non-linear material behavior. Some numerical examples are included to confirm the theoretical results.The authors wish to thank the Spanish Ministerio de Economia y Competitividad for the financial support received through the project DPI2013-46317-R and Generalitat Valenciana through the project PROMETEO/2012/023. The authors are also grateful for the support of the Seventh Framework Programme Initial Training Network Funding under grant number 289361 'Integrating Numerical Simulation and Geometric Design Technology (INSIST)".Tur Valiente, M.; Albelda Vitoria, J.; Marco, O.; Ródenas, J. (2015). Stabilized method of imposing Dirichlet boundary conditions using a recovered stress field. Computer Methods in Applied Mechanics and Engineering. 296:352-375. https://doi.org/10.1016/j.cma.2015.08.001S35237529
2D contact smooth formulation based on the mortar method
No full textIn this paper, we apply a smoothing technique to solve contact problems using a segment-to-segment formulation based on the mortar method. In contact smoothing the C 0 finite element description of the geometry is replaced by an improved smoothed one (usually with C 1 continuity). So far these techniques have been applied to solve contact problems based on node-to-segment interaction. Some numerical examples are solved to compare the performance of the smoothing and non-smoothing formulations. The examples show that the non-smoothed mortar formulation is improved mainly for problems with matching curved surfaces discretized with non-conforming meshes.The authors thank the financial support received from Ministerio de Ciencia y Tecnologia by means of the project DPI2010-20990 and Generalitat Valenciana Programme PROMETEO 2012/023.Tur Valiente, M.; Giner Maravilla, E.; Fuenmayor Fernández, FJ.; Wriggers, P. (2012). 2D contact smooth formulation based on the mortar method. Computer Methods in Applied Mechanics and Engineering. 247-248:1-14. https://doi.org/10.1016/j.cma.2012.08.002S114247-24
Influence of bulk stress on contact conditions and stresses during fretting fatigue
No full text[EN] This paper analyses the effect of bulk stress applied in the specimen on the contact conditions and stresses during a fretting fatigue test. The problem considered corresponds to that of a fretting bridge test using spherical contact pads. A three-dimensional finite element model together with a mesh subdivision h-adaptive procedure has been used. This has allowed for the evaluation of a precise solution at a reasonable computational cost. Finite element results have been compared with existing analytical models.Tur Valiente, M.; Fuenmayor Fernández, F.; Ródenas, J. (2002). Influence of bulk stress on contact conditions and stresses during fretting fatigue. Journal of Strain Analysis for Engineering Design. 37(6):479-492. doi:10.1243/030932402320950107S47949237
Parametric model for the simulation of the railway catenary system static equilibrium problem
No full textDynamic simulations of pantograph catenary interaction are nowadays essential for improving the
performance of railway locomotives, by achieving better current collection at higher speeds and lower
wear of thecollecting parts.The first step in performing these simulations is to compute the static
equilibrium of the overhead line.The initial dropper lengths play an important role in hanging the
contact wire at an appropriate height. From a classical point of view, if one wants to obtain the static
equilibrium configuration of the system for different combinations of dropper lengths, one static pro-
blem must be solved for each combination of lengths, which involves a prohibitive computational cost. In this paper we propose a parametric model of the catenary, including the undeformed dropper lengths as extra-coordinates of the problem. This multidimensional problem is efficiently solved by means of the Proper Generalized Decomposition (PGD) technique, avoiding the curse of dimensionality issue. The capabilities and performance of the proposed method are shown by numerical examples.The authors would like to acknowledge the financial support of the FPU program offered by the Ministerio de Educacion, Cultura y Deporte under Grant number FPU13/04191. The funding from Universitat Politecnica de Valencia and Generalitat Valenciana (PROMETEO/2012/023) are also acknowledged.Gregori Verdú, S.; Tur Valiente, M.; Nadal, E.; Fuenmayor Fernández, FJ.; Chinesta, F. (2016). Parametric model for the simulation of the railway catenary system static equilibrium problem. Finite Elements in Analysis and Design. 115:21-32. https://doi.org/10.1016/j.finel.2016.02.007S213211
Optimización de la geometría de catenarias ferroviarias de alta velocidad
No full text[ES] La fuerza que se genera en el contacto entre el pantógrafo y el cableado de la catenaria ferroviaria cuando circula un vehículo es un factor clave en la captación de la corriente eléctrica. En este trabajo se realiza una optimización de la geometría de una catenaria con el objetivo de conseguir una fuerza de contacto lo más uniforme posible, para así reducir tanto el desgaste de los elementos como la aparición de despegues entre el pantógrafo y la catenaria. Se consideran como variables a optimizar la longitud de las péndolas, que determinan la altura del cable de contacto, y la separación entre ellas. El proceso de optimización se lleva a cabo mediante un algoritmo genético convencional. Para que el proceso tenga un coste computacional razonable, el problema de interacción dinámica entre pantógrafo y catenaria se resuelve de una forma muy eficiente con la utilización de una estrategia de integración dividida en dos bloques. De este estudio se concluye que no solo el comúnmente utilizado pre-sag conduce a un mejor comportamiento en la captación de corriente, sino que pueden existir otras alternativas.Gregori Verdú, S.; Nadal, E.; Tur Valiente, M.; Fuenmayor Fernández, F. (2017). Optimización de la geometría de catenarias ferroviarias de alta velocidad. International Center for Numerical Methods in Engineering (CIMNE). 1328-1341. https://riunet.upv.es/handle/10251/179965S1328134
Finite element periodic catenary model to perform HIL pantograph tests considering non-linear dropper behaviour
No full text[EN] In this paper, we propose a general approach to compute the dynamic response of periodic infinite structures subjected to a moving load. The method only considers one repetitive block of the structure which is modelled by the Finite Element Method. The problem is first shifted to the frequency domain where the periodicity condition is easily applied and then the temporal response is obtained. An infinite periodic catenary system has been chosen to illustrate the proposed formulation. The linear formulation is extended to include the non-linear behaviour of droppers. The efficiency and accuracy of the catenary model obtained makes it very suitable for use in Hardware in the Loop (HIL) pantograph tests. We propose to combine this catenary model with an iterative strategy to achieve the steady-state response of the coupled system and its performance is analysed in a virtual HIL simulation.The authors would like to acknowledge the financial support received from the State Research Agency of the Spanish Science and Innovation Ministry (PID2020-113458RB-I00) and from the Valencian Regional Government (PROMETEO/2021/046).Gil-Romero, J.; Tur Valiente, M.; Gregori Verdú, S.; Correcher Salvador, A.; Fuenmayor Fernández, F. (2022). Finite element periodic catenary model to perform HIL pantograph tests considering non-linear dropper behaviour. Finite Elements in Analysis and Design. 210:1-12. https://doi.org/10.1016/j.finel.2022.103816S11221
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