Examinando por Materia "ELEMENTOS FINITOS"

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    Algoritmo de integración para materiales no lineales considerando los efectos de viscoplasticidad, endurecimiento cinemático no lineal y daño
    (2014-05-07) Gómez-Cataño, J. D. (Juan David)
    In the Finite Element Method (FEM) material non-linearities are considered through incremental formulations in terms of a pseudo-time variable for the case of rate independent models and a real time variable in the case of rate-dependent models. The incremental statement of the problem implies that the constitutive models need to be time-integrated at the local level. In this article we discuss a standard algorithm available in the literature where additionally we have incorporated the effects of non-linear kinematic hardening, viscoplasticity, and damage. The algorithm is incorporated into a FEM code. In order to verify the correctness of our implementation we have particularized the model to the case of a creep law available from literature for solder alloys. Numerical simulation results are compared with experiments taken from the literature.
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    Análisis del proceso de deshidratación de cacao para la disminución del tiempo de secado
    (2013-12-17) Tinoco, Héctor A.; Ospina, D. Y. (Diana Yomali)
    Cocoa is one of the products demanded by the international agricultural market; some multinational companies have invested from its beginnings in research and development, in order to obtain new products. Some factors increase the costs in cocoa-based products, which can be attributed to market conditions (supply and demand), cocoa transformation process, agricultural processes and procedures, among others. This study focuses on a process of industrial transformation that is usually a final step in a series of operations to get dried cocoa beans. Certain variables such as time, temperature, and humidity establish the effectiveness of drying of cocoa. This research suggests the possibility of reducing industrial drying time without affecting the organoleptic properties, changing humidity and temperature. For this proposal experimental tests of drying and computational analysis, using the finite element method to study the drying process, were carried out.
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    PublicaciónAcceso abierto
    Patrones de Turing sobre esferas con crecimiento continuo
    (2013-11-08) Garzón-Alvarado, D. A. (Diego Alexánder); Ramírez-Martínez, Angélica María; Duque-Daza, Carlos Alberto
    We have developed several numerical examples of reaction-diffusion equations with growth surface domain. In this research we use the Schnakenberg reaction model, with parameters in the Turing space. Therefore,numerical tests are performed on the appearence of Turing patterns in spherical surfaces. For the solution of reaction diffusion equations provides a method of settling on surfaces in three dimensions using the finite element method under the total Lagrangian formulation. The results show that the formation of Turing patterns depends on the growth rate of the surface, the type of wave number predicted in the theory of square domains and their stabilization time. These results may explain some phenomena of pattern change on the surface of the skin of animals that exhibit characteristic spots.
  • Miniatura
    PublicaciónAcceso abierto
    Sinterización cerámica por elementos finitos
    (2014-05-06) Arango, N. (Nolasco); Restrepo-Ochoa, J. L. (Jorge Luis); López, N. J. (Nelson de Jesús); Carvajal, L. (Leonardo)
    This paper describes and demonstrates the effectiveness of a finite-element procedure to predict the compactation of a green ceramic isostatics pressed plate during sintering process. The approach is based on the conservation of mass principle and requires for its implementation: i) description of the finite element meshes of the green plate when ejected from the press, and ii) the density of the plate after compactation and sintering process. Numerical compactation predictions have been compared with experimental data. The comparisons reveal that the quantitative predictions regarding diameter and height range correlate closely with the measured values showing a difference of 0.52% in diameter and 0.48% in height and a variation on shrinkage of 3.49%. We consider this to be in good agreement, for most practical purposes.