Examinando por Materia "Mechanical properties"
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Ítem Design and construction of a transducer for bite force registration.(ELSEVIER SCI LTD, 2009-05-29) Isaza JF; Throckmorton GS; Roldán SI; Universidad EAFIT. Departamento de Ingeniería Mecánica; Bioingeniería GIB (CES – EAFIT)This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.Ítem Design and construction of a transducer for bite force registration.(ELSEVIER SCI LTD, 2009-05-29) Isaza JF; Throckmorton GS; Roldán SI; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.Ítem Effect of chemical composition and microstructure on the mechanical behavior of fish scales from Megalops Atlanticus(ELSEVIER SCIENCE BV, 2016-03-01) Gil-Duran, S.; Arola, D.; Ossa, E.A.; Gil-Duran, S.; Arola, D.; Ossa, E.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThis paper presents an experimental study of the composition, microstructure and mechanical behavior of scales from the Megalops Atlanticus (Atlantic tarpon). The microstructure and composition were evaluated by Scanning Electron Microscopy (SEM) and RAMAN spectroscopy, respectively. The mechanical properties were evaluated in uniaxial tension as a function of position along the length of the fish (head, mid-length and tail). Results showed that the scales are composed of collagen and hydroxyapatite, and these constituents are distributed within three well-defined layers from the bottom to the top of the scale. The proportion of these layers with respect to the total scale thickness varies radially. The collagen fibers are arranged in plies with different orientations and with preferred orientation in the longitudinal direction of the fish. Results from the tensile tests showed that scales from Megalops Atlanticus exhibit variations in the elastic modulus as a function of body position. Additional testing performed with and without the highly mineralized top layers of the scale revealed that the mechanical behavior is anisotropic and that the highest strength was exhibited along the fish length. Furthermore, removing the top mineralized layers resulted in an increase in the tensile strength of the scale. © 2015 Elsevier Ltd.Ítem Effect of the mechanical properties on drilling resistance of Al2O3-TiO2 coatings manufactured by atmospheric plasma spraying(ELSEVIER SCIENCE SA, 2013-04-15) Palacio, C. C.; Ageorges, H.; Vargas, F.; Diaz, A. F.; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Al2O3 with 13 and 45wt.% TiO2 microsized powders (6-22 and 13-41µm for each chemical composition) were used as raw materials to coat AISI 1040 steel by atmospheric plasma spraying. The mechanical properties of the coatings were measured by micro-indentation tests, and drilling experiments were carried out using high speed steel (HSS) rotary drill bits of various diameters and varying the load on the drill bits. In order to reduce the effect of the wear on the bit, a new bit was used for each test. According to the results, the drilling test is proposed as a method of determining the mechanical properties of these coatings from the correlation found between coating hardness and drilling resistance. © 2012 Elsevier B.V.Ítem Mechanical responses of plasma sprayed coatings from residual stress measurements and finite element analysis: Effect of the pore network architecture(Universidad de Tarapaca, 2011-01-01) Espinosa, C.C.P.; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)This study aims a better understanding residual stress and stress field within composite plasma sprayed coatings submitted to strains. In order to reach out this objective, residual stress techniques can be implemented for measurements during elaboration of coatings and finite element analyses (FEA) can be conducted on domains resulting from the discretization of Scanning Electron Microscopy (SEM) high resolution pictures of coating structures. TiO 2-Cu and Al 2O 3-13TiO 2 plasma sprayed coatings were considered for demonstrative purposes regarding residual stress measurements and effect of the pore network architecture, respectively. Several operating parameters permitted to manufacture coatings exhibiting different magnitude of residual stress and several porous architectures, in terms of pore content, crack density and crack orientation. Residual stress determined from measurements of deflection during elaboration of TiO 2-Cu coatings allow to identify their nature while numerical simulations show the very significant influence of the network architecture on the stress field within the Al 2O 3-13TiO 2 coatings. Based on the same analyzed structures, other theoretical compositions were considered in the finite element analyses by modifying the intrinsic mechanical properties of the phases. For the considered cases, simulations show the poor influence of the nature of the secondary phase on the stress field within the coatings. Beside these results, the paper proposes a generic methodology and points out its advantages and limits, emphasizing in particular the importance of the representative elementary volume (REV).Ítem Morphological and mechanical characteristics of rigid polyurethane foams(2009-01-01) Restrepo-Zapata, N.C.; Ossa H., E.A.; Mejia, F.C.; Restrepo-Zapata, N.C.; Ossa H., E.A.; Mejia, F.C.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaCellular materials are formed by solid cells in a gaseous core. They exhibit good strength to mass ratio and they are used as insulators and as a core in sandwich composite manufacture. This work describes an extensive study on the structure and physical-mechanical properties of rigid polyurethane (PU) foams. The effect of composition and processing conditions on the mechanical properties were studied. Morphology, specific strength and density were evaluated to determine the optimal levels of processing for a required application. Foam morphology was characterized using stereoscopy and optical microscopy. A basic mechanical property as compression strength was measured in the plateau zone.Ítem Natural flexible armor as an inspirationfor body armor design(Soc. for the Advancement of Material and Process Engineering, 2015-05-21) Alexander Ossa, E.; Alexander Ossa, E.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaAnimals have developed different strategies to protect themselves from environmental and predatory threats. One of these strategies concerns with the development of natural flexible dermal armor, usually consisting of rigid and highly mineralized units (e. g. scales or osteoderms) attached by flexible collagen fibers. These kinds of arrangements have been proven to achieve high flexibility without significant reduction in strength in comparison to monolithic structures. These are in fact features extremely valued by body armor users. This work studies the mechanical characteristics of scales and osteoderms of different animals (including mammals, reptiles and fishes), in order to compare them with other characteristics of the animal itself (like length and mobility) and characteristics of their predators like geometry and composition of their teeth and strength of bite. This comparison extends our knowledge and open new ways of understanding on how to design body armor materials and structures looking into improvements on flexibility and mobility. Copyright 2015. Used by the Society of the Advancement of Material and Process Engineering with permission.Ítem Propiedades físicas y mecánicas de granos de Jatropha curcas cultivadas en Colombia(IMPRENTA UNIV ANTIOQUIA, 2014-01-01) Betancur-Prisco, J.C.; Mira-Hernández, C.; París-Londoño, L.S.; Betancur-Prisco, J.C.; Mira-Hernández, C.; París-Londoño, L.S.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)Biodiesel from Jatropha curcas seeds is one promissory option in the biofuels field. This is a crop that develops in tropical countries which can grow on marginal soils with low irrigation and helps to control the erosion. This bush grows quickly and produces seeds with approximately 35% oil content and it does not compete with food crops. However, for the production of biodiesel from Jatropha to be sustainable and profitable it is required research and technological development at all stages of the production chain. This articleshows the results of a research process that aims the determination of some significant physical and mechanical characteristics of Jatropha curcas seeds. This data are important, because they provide necessary information in the design of equipment and processes for Jatropha curcas oil production; especially, for mechanical oil extraction. As a result of the research process different properties were determined, for example: compression (2.8 mm) and energy (332 N.mm) required for fracture, average dimensions of seeds (length: 10.8 mm/width: 17.8 mm/thickness: 8.6 mm), fractions of shell (38%) and albumen (62%) in the seed, moisture content of seed (5.2%), oil content (29%), calorific value of shell (0.3 MJ/kg) and albumen (0.8 MJ/kg). All these variables are important parameters in the design of equipment, but also are useful to evaluate alternative uses for by-products of the oil extraction process, for example as energy source. Besides, the available information in Colombia about Jatropha is not much.Ítem Relationship between enamel mechanical, chemical, ultrastructural properties and mammalian bite force(Universidad EAFIT, 2021) Fernández Arteaga, Juliana María; Ossa Henao, Edgar AlexánderMammalian enamel is one of the hardest and most mineralized tissues in the body. Its main function is to support the loads generated during the chewing process. Mechanical, chemical and ultrastructural properties are responsible for providing it with the high resistance necessary to withstand constant loads and for making the animal’s tooth functional through its life. Animal bite forces as well as their feeding patterns can influence enamel ultrastructure, improving its behavior when facing chewing loads. A brief review of enamel mechanical and chemical properties as well as a brief review on mammalian enamel decussation characteristics are presented in chapter 2. The methodology used in this study is shown in chapter 3, experimental results in terms of mechanical, chemical and ultrastructural properties are presented in chapter 4. In Chapter 5 the results of the experimentation are analyzed in terms of their statistical correlations and the relationship between enamel properties, bite force, and feeding patterns of the analyzed specimens. Finally the conclusions of this investigation are shown in chapter 6. The bite force of the analyzed animals (BFQ) is related to the elastic modulus of the enamel and that the enamel of the analyzed species shows similar characteristics to human enamel in terms of the variations in mechanical and chemical properties. The properties analyzed were compared in terms of the taxonomic classification or the feeding patterns of the analyzed specimens. The mechanical variables (elastic modulus and hardness) do not seem to be related to taxonomic classification or feeding patterns. The decussation fraction is greater than 0:8 regardless of the taxonomic classification or feeding patterns, enamel thickness and decussated thickness are statistically correlated with decussated band thickness, this could indicate that these variables are important in delaying crack growth. Ultrastructural variables do not seem to depend on taxonomic classification or feeding patterns.