Examinando por Materia "Mechanical characteristics"

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    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 Ingeniería
    Cellular 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.
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    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 Ingeniería
    Animals 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.