Examinando por Materia "Friction"
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Ítem Analytical method for the kinetostatic analysis of the second-class RRR assur group allowing for friction in the kinematic pairs(Springer Berlin Heidelberg, 2010-07-01) Durango, S.; Calle, G.; Ruiz, O.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAEThe calculation of forces in the kinematic pairs of mechanisms by inverse dynamics is usually performed without friction considerations. In practice, when examination of articulated mechanisms takes into account friction, the solution of the inverse dynamics results in a complex procedure. If a modular approach for the inverse dynamics is used, then exact solutions are available, but not necessarily are practical. For example, the analytical solution for a second-class first-type Assur group is a 16th degree equation. Previous researches proposed an approximated but practical (graphical) method to calculate the forces on the kinematic pairs taking into account the friction forces. In this article, an analytical interpretation of the Artobolevski approximated method is developed for the second-class Assur group with three rotational pairs. The final results for the reactions calculated with the implemented method present a good approximation with respect to the graphical solution. Future work should consider friction forces not only in second-class groups with rotational joints, but also in second-class groups with prismatic joints and high-class Assur groups. Copyright © 2010 by ABCM.Ítem Correlations between thermal and tensile behavior with friction coefficient in copolyamides 6/12(Elsevier Ltd, 2017-02-15) Álvarez-Láinez, M.L.; Palacio R., J.A.; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)Although polyamide 6 (PA6) obtained from e-caprolactame (CL) is an engineering polymer with outstanding properties used in sliding applications, it exhibits low impact strength and high water absorption. Those are some of the reasons why copolymerization between CL and laurolactame (LL) is desired. In this work, copolymers from 0–100 wt% LL are prepared to evaluate crystallinity, melting behavior, tensile properties and those properties are correlated with coefficient of friction. Experimental results show that PA6 (0 wt%) crystallinity and elasticity modulus are higher than those obtained from 100 wt%LL (PA12), but friction coefficient in PA6 is lower than that of PA12. While with 60 wt% LL crystallinity and elastic modulus reach a minimum value, with 350% elongation and coefficient of friction they register a maximum value. Our results suggest that crystallinity and elastic modulus are opposed to coefficient of friction. The absence of hydrogen bonds produces irregularities in the chain, reducing the crystal formation; such behavior is a consequence of copolymerization. Our findings will help to customize copolyamide, modulate the response between mechanical properties and friction behavior, as well as evaluate when it is necessary to add lubricants in the copolymer formulations. © 2016 Elsevier B.V.Ítem Diseño de un freno prony para la medición de potencia(Universidad EAFIT, 2008) Gutiérrez Benítez, Laura; Corrales Posada, Carlos Andrés; Quirós Morales, Luis FernandoÍtem Espumas flexibles para la sustitución de espumas de pulido utilizadas en la industria cerámica local: caracterización física y mecánica(Universidad EAFIT, 2008) Vélez Velásquez, Andrés Felipe; Jaramillo Serna, Juan Sebastián; Restrepo Zapata, Nora CatalinaÍtem Influence of Tribological Parameters on Coefficient of Friction between Polypropylene and Skin(Universidad EAFIT, 2014-06-24) Pavón Palacio, J J; Villarraga Ossa, J A; Tobon Espinosa, D F; Universidad de AntioquiaÍtem Prueba de una microturbina tipo Michel-Banki de baja potencia(Universidad EAFIT, 2015) Giraldo Jiménez, Santiago; París Londoño, Luis SantiagoÍtem Rediseño de un sistema de lubricación centralizado en una línea de transporte de botellas en una empresa de bebidas(Universidad EAFIT, 2009) Alzate Restrepo, Andrés Mauricio; Álvarez Torres, DenisÍtem Resistencia de las discontinuidades rocosas al esfuerzo cortante(Universidad EAFIT, 2014) Correa Villa, Elías; Echeverri Ramírez, Gloria ElenaEn este trabajo se evalúa la resistencia pico, resistencia residual y las propiedades de deformabilidad en el rango elástico tanto al corte como en el sentido normal para discontinuidades estructurales onduladas de macizos rocosos -- Esto se logró establecer mediante la cuantificación de la geometría de las ondulaciones presentes en las discontinuidades estructurales, aplicando la metodología propuesta por Goodman para la medición de parámetros en campo, los cuales permiten calcular el ángulo de rugosidad (i) en forma más realista -- El procedimiento se realizó en once perfiles lineales obtenidos en diabasas de la Formación Volcánica presente en el departamento del Valle del Cauca, vertiente pacífica en la cordillera Occidental -- De cada perfil se calcularon múltiples valores del ángulo rugosidad (i) para diferentes magnitudes de desplazamiento y con este conjunto de valores se obtuvieron las envolventes de resistencia pico y residual y los parámetros de deformación en el rango elástico y post-pico