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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento de t?xteis t?cnicos para refor?o de comp?sitos polim?ricos

Lima, Jos? Henrique Batista 02 May 2012 (has links)
Made available in DSpace on 2014-12-17T14:58:15Z (GMT). No. of bitstreams: 1 JoseHBL_DISSERT_PARCIAL.pdf: 2505963 bytes, checksum: 1b82ec8a8147b2b7e13d0af6880855f0 (MD5) Previous issue date: 2012-05-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Materials denominated technical textiles can be defined as structures designed and developed with function to fulfill specific functional requirements of various industrial sectors as are the cases of the automotive and aerospace industries. In this aspect the technical textiles are distinguished from conventional textile materials, in which the aesthetic and of comfort needs are of primordial importance. Based on these considerations, the subject of this dissertation was established having as its main focus the study of development of textile structures from aramid and glass fibers and acting in order to develop the manufacture of composite materials that combine properties of two different structures, manufactured in an identical operation, where each structure contributes to improving the properties of the resulting composite material. Therefore were created in laboratory scale, textile structures with low weight and different composition: aramid (100%), glass (100%) and aramid /glass (65/35%), in order to use them as a reinforcing element in composite materials with polyester matrix. These composites were tested in tension and its fracture surface, evaluated by MEV. Based on the analysis of mechanical properties of the developed composites, the efficiency of the structures prepared as reinforcing element were testified by reason of that the resistance values of the composites are far superior to the polyester matrix. It was also observed that hybridization in tissue structure was efficient, since the best results obtained were for hybrid composites, where strength to the rupture was similar to the steel 1020, reaching values on the order of 340 MPa / Os materiais denominados t?xteis t?cnicos podem ser definidos como estruturas projetadas e desenvolvidas com a fun??o de atender a requisitos funcionais espec?ficos de diversos setores da ind?stria, caso da ind?stria automotiva e aeroespacial. Nesse aspecto, distinguem-se dos materiais t?xteis convencionais, nos quais as necessidades est?ticas e de conforto t?m import?ncia primordial. Com base nessas considera??es, o tema dessa disserta??o foi estabelecido tendo como enfoque principal o estudo do desenvolvimento de estruturas t?xteis a partir de fibras de aramida e de vidro, atuando no sentido de elaborar a fabrica??o de materiais comp?sitos que combinem propriedades de duas estruturas diferentes, fabricadas em uma mesma opera??o, onde cada estrutura contribui para melhoria das propriedades do material comp?sito resultante. Para tanto foram desenvolvidas em escala laboratorial estruturas t?xteis de baixa gramatura e composi??o diferenciada de aramida (100%), vidro (100%) e aramida/vidro (65/35%) para utiliza??o como elemento refor?ante em comp?sitos com matriz de poli?ster. Os comp?sitos produzidos foram ensaiados em tra??o e sua superf?cie de fratura avaliada por MEV. Com base nas analises das propriedades mec?nicas dos comp?sitos desenvolvidos, observou-se a efici?ncia das estruturas ou elaboradas como elemento refor?ante tendo em vista que os valores de resist?ncia dos comp?sitos foram muito superiores ? matriz de poli?ster. Tamb?m foi observado que a hibridiza??o na estrutura dos tecidos foi eficiente, uma vez que os melhores resultados obtidos foram para os comp?sitos h?bridos, onde a resist?ncia na ruptura foi semelhante ? do a?o 1020, atingindo valores na ordem de 340 MPa

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