Examinando por Autor "Ossa, A."

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    Características de adhesión entre fibras de queratina y poliéster insaturado
    (IMPRENTA UNIV ANTIOQUIA, 2008-01-01) Paniagua, M.; Ossa, A.; Ruiz, G.; Paniagua, M.; Ossa, A.; Ruiz, G.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
    This work presents the methods and results employed to find the adhesion characteristics between keratin fibers and unsaturated polyester as matrix material. The fibers were conditioned prior to testing using four different methods in order to establish the effect of these treatments on the adhesion to the matrix by means of i) monofilament pull-out testing, as direct method; and ii) Lamina tensile tests as indirect method to analyze the adhesion in the fracture zone with the help of electron microscopy (SEM).
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    Nature-Inspired Protecto-Flexible Impact-Tolerant Materials
    (Wiley-VCH Verlag, 2020-01-01) Estrada, S.; Ossa, A.; Estrada, S.; Ossa, A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
    The search for impact-tolerant, light-weight flexible materials has challenged materials scientists and engineers for decades. In this quest, many researchers have focused on studying natural armor as a guide to propose bioinspired materials with enhanced properties. The energy dissipation and flexibility mechanisms activated at different hierarchical structural levels of natural systems are used here as a guide to improve the energy and flexibility of synthetic materials. In particular, fish scales and osteoderms are selected as proper biological models to develop a novel family of cost-effective bioinspired protecto-flexible (Pf) materials. Furthermore, a bullet-proof protecto-flexible prototype is manufactured and tested. The ballistic tests suggest that under real stringent conditions, the system is capable of absorbing high levels of energy while remaining flexible enough to allow movement to the user. Remarkably, the material system developed allows its implementation into realistic high volumes of production with low added costs. Consequently, the proposed strategy for developing bioinspired Pf materials will enable the development of the next generation of high-performance impact-resistant materials. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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    Zylerberg, 1985 Contributions of the layer topology and mineral content to the elastic modulus and strength of fish scales
    (ELSEVIER SCIENCE BV, 2018-02-01) Murcia, S.; Miyamoto, Y.; Varma, M.P.; Ossa, A.; Arola, D.
    Fish scales are an interesting natural structural material and their functionality requires both flexibility and toughness. Our previous studies identified that there are spatial variations in the elastic properties of fish scales corresponding to the anatomical regions, and that they appear to be attributed to changes in the microstructure. In the present study, a model is proposed that describes the elastic behavior of elasmoid fish scales in terms of the relative contributions of the limiting layer and both the internal and external elasmodine. The mechanical properties of scales from the Megalops atlanticus (i.e. tarpon) were characterized in tension and compared with predictions from the model. The average error between the predicted and the experimental properties was 7%. It was found that the gradient in mineral content and aspect ratio of the apatite crystals in the limiting layer played the most important roles on the elastic modulus of the scales. Furthermore, misalignment of plies in the external elasmodine from the longitudinal direction was shown to reduce the elastic modulus significantly. This is one approach for modulating the fish scale flexibility for a high mineral content that is required to increase the resistance to puncture. © 2017