Examinando por Materia "Numerical models"

Mostrando 1 - 8 de 8
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    Ítem
    Determination of the technical state of suspension elements based on the OMA-LSCE method
    (Collegio Ingegneri Ferroviari Italiani, 2012-01-01) Castañeda, L.; Martinod, R.; Betancur, G.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    A study is established regarding the behavior of the vehicle under the influence of the damping elements, proposing a methodology for the validation of the technical state of the dampers through the registration of dynamic variables under commercial operating conditions of the vehicle, by applying the Operational Modal Analysis COMA) technique via Least-Square Complex Exponential (LSCE) method to experimental tests and numeric simulations to a multi-body system (MBS) model. The OMA-LSCE method is applied to the signals acquired during a test performed on a passenger of a three- car unit in typical commercial travel operation. From the signals in time domain of each section of the segment, the respective discrete function PSD is calculated. Once the model is defined, a set of numeric simulation is executed according to the design of the experiment. The results of the numeric simulations show that the natural frequency generates a lineal regressive model with correlation coefficient values.
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    Ítem
    Determinazione dello stato tecnico degli elementi delle sospensioni sulla base del metodo OMA-LSCE
    (Collegio Ingegneri Ferroviari Italiani, 2012-01-01) Castañeda, L.; Martinod, R.; Betancur, G.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    A study is established regarding the behavior of the vehicle under the influence of the damping elements, proposing a methodology for the validation of the technical state of the dampers through the registration of dynamic variables under commercial operating conditions of the vehicle, by applying the Operational Modal Analysis COMA) technique via Least-Square Complex Exponential (LSCE) method to experimental tests and numeric simulations to a multi-body system (MBS) model. The OMA-LSCE method is applied to the signals acquired during a test performed on a passenger of a three- car unit in typical commercial travel operation. From the signals in time domain of each section of the segment, the respective discrete function PSD is calculated. Once the model is defined, a set of numeric simulation is executed according to the design of the experiment. The results of the numeric simulations show that the natural frequency generates a lineal regressive model with correlation coefficient values.
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    Ítem
    Meta-modeling of Lattice Mechanical Responses via Design of Experiments
    (Institute of Electrical and Electronics Engineers Inc., 2020-01-01) Montoya-Zapata D.; Acosta D.A.; Cortes C.; Pareja-Corcho J.; Moreno A.; Posada J.; Ruiz-Salguero O.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    In the context of lattice manufacturing, the problem of mechanical and structural characterization of large lattice domains is relevant. Lattice materials are used in engineering (e.g. in energy absorption and heat conduction) and biomedical (e.g. bone implants and artificial tissues) applications. However, the numerical simulation of large lattice domains is limited by its complicated geometry, which hinders the meshing stage and produces intractable finite element meshes. The existing efforts to simulate large lattice domains are based on the generation of simplified homogeneous domains equipped with material properties that approximate the behavior of the lattice domain equipped with the bulk material. Using this approach, one can estimate the displacements field over the lattice domain using a lighter mesh and a cheaper simulation. However, since stresses are influenced by geometrical conditions, the stresses of the simplified domain do not match the stresses of the lattice domain. As a response to this limitation, this article proposes a methodology based on the systematic use of design of experiments to devise meta-models to estimate the mechanical response of lattice domains. The devised meta-models can be integrated with material homogenization to allow the mechanical characterization of large lattice domains. In this paper, we apply the proposed methodology to develop meta-models for the estimation of the von Mises stress in Schwarz Primitive lattice domains. Results show that the proposed methodology is able to generate efficient and accurate meta-models whose inputs are based on the displacements on the boundary of the Schwarz cell. Therefore, numerical simulations with the homogeneous simplified domain can be used to feed the meta-models. Additional work is still required to integrate the developed meta-models with material homogenization to test large Schwarz Primitive lattice domains under working loads. © 2020 IEEE.
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    Ítem
    Meta-modeling of Lattice Mechanical Responses via Design of Experiments
    (Institute of Electrical and Electronics Engineers Inc., 2020-01-01) Montoya-Zapata D.; Acosta D.A.; Cortes C.; Pareja-Corcho J.; Moreno A.; Posada J.; Ruiz-Salguero O.; Montoya-Zapata D.; Acosta D.A.; Cortes C.; Pareja-Corcho J.; Moreno A.; Posada J.; Ruiz-Salguero O.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In the context of lattice manufacturing, the problem of mechanical and structural characterization of large lattice domains is relevant. Lattice materials are used in engineering (e.g. in energy absorption and heat conduction) and biomedical (e.g. bone implants and artificial tissues) applications. However, the numerical simulation of large lattice domains is limited by its complicated geometry, which hinders the meshing stage and produces intractable finite element meshes. The existing efforts to simulate large lattice domains are based on the generation of simplified homogeneous domains equipped with material properties that approximate the behavior of the lattice domain equipped with the bulk material. Using this approach, one can estimate the displacements field over the lattice domain using a lighter mesh and a cheaper simulation. However, since stresses are influenced by geometrical conditions, the stresses of the simplified domain do not match the stresses of the lattice domain. As a response to this limitation, this article proposes a methodology based on the systematic use of design of experiments to devise meta-models to estimate the mechanical response of lattice domains. The devised meta-models can be integrated with material homogenization to allow the mechanical characterization of large lattice domains. In this paper, we apply the proposed methodology to develop meta-models for the estimation of the von Mises stress in Schwarz Primitive lattice domains. Results show that the proposed methodology is able to generate efficient and accurate meta-models whose inputs are based on the displacements on the boundary of the Schwarz cell. Therefore, numerical simulations with the homogeneous simplified domain can be used to feed the meta-models. Additional work is still required to integrate the developed meta-models with material homogenization to test large Schwarz Primitive lattice domains under working loads. © 2020 IEEE.
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    Ítem
    Meta-modeling of Lattice Mechanical Responses via Design of Experiments
    (Institute of Electrical and Electronics Engineers Inc., 2020-01-01) Montoya-Zapata D.; Acosta D.A.; Cortes C.; Pareja-Corcho J.; Moreno A.; Posada J.; Ruiz-Salguero O.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
    In the context of lattice manufacturing, the problem of mechanical and structural characterization of large lattice domains is relevant. Lattice materials are used in engineering (e.g. in energy absorption and heat conduction) and biomedical (e.g. bone implants and artificial tissues) applications. However, the numerical simulation of large lattice domains is limited by its complicated geometry, which hinders the meshing stage and produces intractable finite element meshes. The existing efforts to simulate large lattice domains are based on the generation of simplified homogeneous domains equipped with material properties that approximate the behavior of the lattice domain equipped with the bulk material. Using this approach, one can estimate the displacements field over the lattice domain using a lighter mesh and a cheaper simulation. However, since stresses are influenced by geometrical conditions, the stresses of the simplified domain do not match the stresses of the lattice domain. As a response to this limitation, this article proposes a methodology based on the systematic use of design of experiments to devise meta-models to estimate the mechanical response of lattice domains. The devised meta-models can be integrated with material homogenization to allow the mechanical characterization of large lattice domains. In this paper, we apply the proposed methodology to develop meta-models for the estimation of the von Mises stress in Schwarz Primitive lattice domains. Results show that the proposed methodology is able to generate efficient and accurate meta-models whose inputs are based on the displacements on the boundary of the Schwarz cell. Therefore, numerical simulations with the homogeneous simplified domain can be used to feed the meta-models. Additional work is still required to integrate the developed meta-models with material homogenization to test large Schwarz Primitive lattice domains under working loads. © 2020 IEEE.
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    Ítem
    The Paleogene arcs of the northern Andes of Colombia and Panama: Insights on plate kinematic implications from new and existing geochemical, geochronological and isotopic data
    (ELSEVIER SCIENCE BV, 2018-12-06) Cardona A.; León S.; Jaramillo J.S.; Montes C.; Valencia V.; Vanegas J.; Bustamante C.; Echeverri S.; Cardona A.; León S.; Jaramillo J.S.; Montes C.; Valencia V.; Vanegas J.; Bustamante C.; Echeverri S.; Universidad EAFIT. Departamento de Ciencias; Geología Ambiental y Tectónica
    The northern Andes of Colombia comprise two non-cogenetic Paleogene arcs formed in contrasting geodynamic settings including continental and oceanic domains. New whole-rock geochemistry and isotopic constraints, together with a review of 332 geochemical, 76 isotopic and 204 geochronological data from Paleocene to Eocene volcanic and plutonic rocks exposed in central and western Colombia and Panama, are used to evaluate cause-effect relations between regional plate kinematics and the spatio-temporal distribution of the circum-Caribbean magmatic arcs. Short-lived, ~60–45 Ma arc-like magmatism in the Central Cordillera of Colombia was emplaced in a thickened continental crust due to the oblique subduction of the Caribbean oceanic plate underneath South America, as suggested by the high Sr/Y ratios. Conversely, the Panama Arc, and its poorly explored extension in the northwestern segment of the Western Cordillera of Colombia document a major phase of tholeiitic to calc-alkaline arc magmatism between ~71 Ma and ~34 Ma, mostly derived from a hydrated mantle wedge, and emplaced in an oceanic plateau crust. This arc record a major phase of magmatic activity between 40 Ma and 50 Ma that can be associated to changes in the convergence direction and subduction rates of the Farallon plate. Farther to the south, in the Pacific region of Colombia, Eocene arc-related rocks from the Timbiqui Complex show a geochemical signature that suggests a magmatic origin from melting of both a subduction-modified mantle and lower tectonically thickened crust. A possible interpretation for the Pacific and Western Colombia-Panama Arc systems, and its analogous in Ecuador, recall an Aleutian-type convergent margin in which the continental arc laterally switches to a purely oceanic system along the trailing edge of the Caribbean plate as consequence of eastward subduction of the Farallon plate. © 2018 Elsevier B.V.
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    A study of the effect of the transition curve in the coupling elements between the carbody and the bogie
    (INDERSCIENCE ENTERPRISES LTD, 2014-01-01) Martinod, Ronald M.; Betancur, German R.; Osorio, Jose F.; Castaneda, Leonel F.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    This work describes an analysis of the effect of the transition curves in the coupling elements between the carbody and the bogie, by means of recorded variables under commercial operation conditions of a railway vehicle. A set of field tests are developed and applied to the railway system as a basis to validate a numerical model. The dataset is obtained from a numerical model based on the multi-body systems theory using a transient method. The study focuses on the dynamic evaluation of the vehicle to determine the transversal dynamic effect generated by the circulation in the transition curve sections, especially in curves with short radius. The work includes a case study of a passenger railway, and it is used to identify aspects of the railway system that could be improved by the operators, such as inspection routines, rail track design and elements subjected to considerable loads. Copyright © 2014 Inderscience Enterprises Ltd.
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    Study of the state a Francis turbine
    (Politechnika Gdanska, Wydzial Oceanotechniki i Okretownictwa, 2013-04-01) Zóltowski, M.; Zóltowski, B.; Castaneda, L.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    This paper presents a methodology to evaluate the technical state of a Francis turbine by shaft rotor dynamic simulation. There are several rotor dynamic criteria that define the technical state of a turbo-machine. To feed the shaft rotor dynamic model this delivers the required information to accomplish the technical assessment. The numerical rotor dynamic model uses as input, the field forces obtained by the fluid-solid interaction analysis undertaken over the blades of the runner. The rotor dynamic numerical simulations allow to determinate the record-in-time of the displacements of any point along the shaft. This information is relevant for diagnosis tasks, because it is possible to decompose it spectrally and to estimate the severity of the vibrations. Comparing the results of the numerical model against those obtained from machines that operates under normal conditions, it is possible to determinate the technical state of the turbo-machine. This allows studying the stability of the turbine working on several operation ranges. A Francis turbine is a very complex machine that involves many physical phenomena of different nature. In this way, the hydraulic input forces needed by the rotor dynamic model should not be assumed but calculated directly from the fluid interaction over the turbine structure.