Examinando por Materia "DEFORMACIONES"

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    Ítem
    Experiment design in compliant mechanisms and kinematic identification of parallel mechanisms
    (Universidad EAFIT, 2010) Restrepo Arango, David; Ruíz Salguero, Oscar Eduardo
    This article discusses a procedure for force-displacement modeling compliant mechanisms by using a design of computer experiments methodology -- This approach produces a force-displacement meta-model that is suited for real-time control of compliant mechanisms -- The term meta-model is used to represent a simplified and efficient mathematical model of unknown phenomena -- The meta-modeling of compliant mechanisms is performed from virtual experiments based on factorial- and space-filling design of experiments -- The procedure is used to model the quasi-static behavior of the HexFlex compliant mechanism -- The HexFlex is a parallel compliant mechanism for nano-manipulation that allows six degrees of freedom of its moving stage -- The meta-model of the HexFlex is calculated from experiments with the Finite Element Method (FEM) -- The obtained meta-model for the HexFlex is linear for the range of movement of the mechanism -- The accuracy of the meta-model was calculated conducting a set of computer experiments with random uniform distribution of the input forces -- Three criteria were calculated in each displacement direction (x, y, z, θx, θy, θz) comparing the meta-model prediction with respect to the results of the virtual experiments: 1. maximum of the absolute value of the error, 2. relative error, and 3. root mean square error -- The maximum errors were founded adequate with respect to demanding manufacturing tolerances (absolute errors) and lower than errors reported by other authors (relative errors)
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    Spring–particle model for hyperelastic cloth
    (Universidad Nacional de Colombia, 2007-03) García, Manuel; Gómez, Mario; Ruíz, Óscar; Boulanger, Pierre; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
    Este artículo presenta un modelo computacional para la simulación de telas hiperelásticas -- El modelo propuesto tiene un enfoque multi−partículas y simula la interacción de un material textil con un objeto deformante -- La tela está representada por mallas rectangulares compuestas por resortes, este hecho permite al modelo comportarse ortotrópicamente y en consecuencia es posible simular sus propiedades en ambos sentidos -- Las relaciones constitutivas del material preservan las capacidades hiperelásticas naturales de la tela -- En el modelo desarrollado aquí, inicialmente la tela se encuentra en su estado natural no deformado -- Luego se le da una deformación inicial que garantice el no contacto o intersección con el objeto deformante -- Finalmente, la tela deformada es liberada, en consecuencia ella comienza a moverse iterativamente hacia a una posición de equilibrio -- La posición final de equilibrio es alcanzada cuando las fuerzas internas son balanceadas por las fuerzas externas de contacto causadas por el objeto -- Esto se logra cuando el criterio de parada ha sido satisfecho
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    Ítem
    Spring–particle model for hyperelastic cloth
    (2005-05) García, Manuel; Gómez, Mario; Ruíz, Óscar; Boulanger, Pierre; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
    This article presents a computational model to simulate the deformation of hyperelastic fabrics -- The model is based on a spring−particle approach and it simulates the interaction of a textile tissue with a forming body -- The fabric is represented by rectangular meshes of springs -- This fact enables the model to behave orthotropically and therefore it is possible to simulate the warp and weft properties -- The constitutive relations preserve the natural hyperelastic capabilities of the cloth -- In the model developed herein, initially the cloth lies in its relaxed un−deformed state -- Then it is given an initial deformation that guarantees no contact nor intersection with the forming rigid body -- Finally, the deformed cloth is realised, and moves iteratively towards an equilibrium location -- The final equilibrium location is reached when the internal forces are balanced by the external contact forces caused by the rigid object -- This is achieved when the stop criterion has been satisfied