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Previous issue date: 2013-12-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / As most current studies, reinforced plastics have been, in recent years, a viable alternative in building structural elements of medium and large, since the lightness accompanied by high performance possible. The design of hybrid polymer composites (combination of different types of reinforcements) may enable structural applications thereof, facing the most severe service conditions. Within this class of composite materials, reinforced the underlying tissues hybrid high performance are taking space when your application requires high load bearing and high rigidity. The objective of this research work is to study the challenges in designing these fabrics bring these materials as to its mechanical characterization and fracture mechanisms involved. Some parameters associated with the process and / or form of hybridization stand out as influential factors in the final performance of the material such as the presence of anisotropy, so the fabric weave, the process of making the same, normative geometry of the specimens, among others. This sense, four laminates were developed based hybrid reinforcement fabrics involving AS4 carbon fiber, kevlar and glass 49-E as the matrix epoxy vinyl ester resin (DERAKANE 411-350). All laminates were formed each with four layers of reinforcements. Depending on the hybrid fabric, all the influencing factors mentioned above have been studied for laminates. All laminates were manufactured industrially used being the lamination process manual (hand-lay-up). All mechanical characterization and study of the mechanism of fracture (fracture mechanics) was developed for laminates subjected to uniaxial tensile test, bending in three and uniaxial compression. The analysis of fracture mechanisms were held involving the macroscopic, optical microscopy and scanning electron microscopy / Conforme estudos mais atuais, os pl?sticos refor?ados v?m sendo, nos ?ltimos anos, uma alternativa vi?vel na constru??o de elementos estruturais de m?dio e grande porte, desde que a leveza acompanhada de alto desempenho seja poss?vel. A concep??o de comp?sitos polim?ricos h?bridos (combina??o entre tipos diferentes de refor?os) pode possibilitar aplica??es estruturais dos mesmos, frente ?s mais adversas condi??es de servi?os. Dentro dessa classe de materiais comp?sitos, os refor?ados a base de tecidos h?bridos de alto desempenho v?m tomando espa?o quando a sua aplica??o requer alto suporte de carga e alta rigidez. O objetivo desse trabalho de investiga??o ? o estudo da influ?ncia que esses tecidos trazem na concep??o desses materiais quanto a sua caracteriza??o mec?nica e mecanismos de fratura envolvidos. Alguns par?metros associados ao processo e/ou forma de hibridiza??o se destacam como fatores influenciadores no desempenho final do material tais como a presen?a de anisotropia, forma da trama tecido, processo de confec??o dos mesmos, geometria normativa dos corpos de prova, entre outros. Neste sentido, quatro laminados comp?sitos foram desenvolvidos ? base de tecidos de refor?os h?bridos envolvendo fibras de carbono AS4, kevlar 49 e vidro-E e como matriz a resina ep?xi ?ster vin?lica (DERAKANE 411-350). Todos os laminados comp?sitos foram constitu?dos com quatro camadas de refor?os. Dependendo do tipo de tecido h?brido, todos os fatores influenciadores acima mencionados foram estudados para os laminados. Todos os laminados foram fabricados industrialmente sendo empregado o processo de lamina??o manual (hand-lay-up). Todo o estudo da caracteriza??o mec?nica e do mecanismo de fratura (fratura mec?nica) foi desenvolvido para os laminados submetidos aos ensaios mec?nicos de tra??o uniaxial, flex?o em tr?s e compress?o uniaxial. As an?lises dos mecanismos de fratura foram realizadas envolvendo a macroscopia, microscopia ?tica e eletr?nica de varredura
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12868 |
| Date | 09 December 2013 |
| Creators | Oliveira, Jorge Fernando de Sousa |
| Contributors | CPF:16080564491, http://lattes.cnpq.br/1196595599227394, Silva, Luiz Claudio Ferreira da, CPF:79098630472, http://lattes.cnpq.br/3812459994118013, Santos, Marco Antonio dos, CPF:18471200082, Le?o, Mirt?nia Antunes, CPF:38400898753, http://lattes.cnpq.br/9156822767910160, Freire J?nior, Raimundo Carlos Silv?rio, CPF:02306444498, http://lattes.cnpq.br/1042806990155996, Aquino, Eve Maria Freire de |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncia e Engenharia de Materiais, UFRN, BR, Processamento de Materiais a partir do P?; Pol?meros e Comp?sitos; Processamento de Materiais a part |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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