Documents published in Scipedia

• Comparison of axial loads from design live load models and real trucks on existing 3D-truss bridges in Mexico

  A. Hernández-Martínez, A. García-Soto, J. Valdes-Vazquez

  Revista Mexicana de Métodos Numéricos (2023). Vol. 7, 2

  
  

  Abstract

  The load effects to which bridge systems and structural elements are subjected to due to vehicular passage are estimated using live load models contained in bridge design codes. Those live load models are frequently derived for girder bridges subjected to shear forces and bending moments. However, other type of bridges, as truss bridges and others, can be subjected to other forces too, for instance axial loads and other effects. In Mexico, in past decades 3D-truss bridges based on a structural system known as “Tridilosa” were designed and built. The live load models to analyze them were widely used to design girder bridges; moreover, the traffic at the time may differ from more recent trucks and vehicles. This paper investigates the adequacy of live load models from codified design to represent load forces on the referred 3D-truss bridges, as compared to realistic Mexican traffic from WIM (weigh-in-motion) data. The results show that live load models in bridge codes are not necessarily adequate to assess forces in the existing 3D-truss (“Tridilosa”) bridges in Mexico.

  Abstract
  The load effects to which bridge systems and structural elements are subjected to due to vehicular passage are estimated using live load models contained in bridge design [...]

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• Influence of mesh size on accuracy results in seismically excited water tanks

  A. Hernández-Martínez, H. Hernández–Barrios, A. García–Soto, J. Valdés–Vázquez

  Revista Mexicana de Métodos Numéricos (2018). Vol. 2, 5

  
  

  Abstract

  The aim of this article is to present the influence of mesh spacing in the error parameters computed for rectangular tanks seismically excited. The potential flow theory is considered using the finite difference method to set a linear numerical formulation due to its simplicity and relatively low computation time, compared with those methods that try to solve directly the Navier–Stokes equations. Wave height on the free surface, as well as pressure, shear force and overturning moment at the tanks wall base are used as parameters for the error evaluation.

  Abstract
  The aim of this article is to present the influence of mesh spacing in the error parameters computed for rectangular tanks seismically excited. The potential flow theory is [...]

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• Una formulación acoplada sólido-estructura para el análisis de vigas de concreto postensado

  J. Valdes-Vazquez, C. Andrade-Moreno, A. García-Soto, A. Hernández-Martínez, J. Valdés-Vázquez, F. Luna-Rodríguez

  Revista Mexicana de Métodos Numéricos (2018). Vol. 2, 4

  
  

  Abstract

  Se presenta una formulación numérica en base al método de los elementos finitos para obtener los esfuerzos y desplazamientos de vigas de concreto postensado. La formulación acopla los cables de postensado con la formulación del sólido, considerando al cable como estructura con apoyos intermedios embebidos en el sólido, lo que es una alternativa novedosa y la principal aportación de este trabajo, ya que no sólo es factible de implementarse con elementos finitos como aquí se muestra, sino que es versátil, en el sentido de que cualquier combinación de carga común y condiciones de apoyo puede representarse con el modelo; pero además, el modelo también es de aplicación práctica para el análisis y diseño de trabes de concreto postensado. El método es validado comparándolo con una alternativa reportada en la literatura, y mediante tres ejemplos con cargas diferentes, con los que se muestra que la formulación propuesta da muy buenos resultados. Está alternativa mediante métodos numéricos, puede extenderse a casos más complejos en el futuro, ya que explota la conveniencia de los elementos finitos, que son más precisos y de más amplia aplicación que otros métodos simplificados, comúnmente usados para diseñar vigas de concreto postensado.

  Abstract
  Se presenta una formulación numérica en base al método de los elementos finitos para obtener los esfuerzos y desplazamientos de vigas de concreto postensado. [...]

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• Dynamic Analysis of Hypar Membrane Structures Subjected to Seismic Excitations

  J. Valdes-Vazquez, A. García-Soto, A. Hernández-Martínez

  Rev. int. métodos numér. cálc. diseño ing. (2019). Vol. 35, (1), 11

  
  

  Abstract

  The seismic response of tensile membrane structures (TMS) is investigated. To the authors knowledge, this is the first study on TMSs subjected to a seismic record reported in the literature. A type of membrane structures usually considered as a reference in other works are employed in the present study. The selected hyperbolic-paraboloid fabric structures, also referred as hypar TMSs, are subjected to an earthquake accelerogram from a relatively large earthquake recorded at Norcia, Italy. To obtain the TMSs seismic re- sponse, a finite element formulation reported in a previous study, and which accounts for wrinkling phenomena, orthotropic material modeling, and geometrical nonlinearity, is employed. The analyses are performed in two stages; first for the prestressed case and then the seismic loading is added. It is found that the seismic response of TMSs should not be disregarded by designers beforehand, since important increments in the dynamic response of the displacements produce an incremet of around 9% for stresses. However, a very important increment of around 80% for support reaction forces is computed, when compared with the static case. It is also found that the orientation of the frame-supporting structure has a significant impact on the computed seismic reactions.

  Abstract
  The seismic response of tensile membrane structures (TMS) is investigated. To the authors knowledge, this is the first study on TMSs subjected to a seismic record reported [...]

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