Aquino, Eve Maria Freire deFontes, Raphael Siqueira2018-04-162018-04-162017-12-14FONTES, Raphael Siqueira. Compósitos poliméricos reforçados por tecidos multiaxiais acoplados: anisotropia, configuração e concentração da deformação. 2017. 148f. Tese (Doutorado em Engenharia Mecânica) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2017.https://repositorio.ufrn.br/jspui/handle/123456789/25067The proposal of this Doctoral Thesis is to determine the influence on the mechanical response of composite laminates based on E-glass multiaxial Non-Crimp Fabrics and epoxy vinyl ester matrix, with the presence of geometric discontinuity, here characterized by a circular hole. In this study of the stress concentration phenomenon, emphasis is given to the strain behavior in the vicinity of the hole, since the reinforcing fabric characteristic, whose basic layers are coupled by stitching, making them more compact in their load support capacity. This study is developed from the strain measurement in the vicinity of the hole, using the technique of measurement by strain gages, during uniaxial tensile tests. Finally, the effect of the presence of the geometric discontinuity will be presented in quantitative terms, by means of the Residual Strength (RS), Residual Modulus (RM) and the Stress Concentration Factors (K, obtained by different analytical methods), in addition to the determination of strain distributions (obtained from strain gage measurements) in the vicinity of the hole in the laminates under study, in 0°, 90° and 45° orientations of the specimens. These distributions are validated using the analytical solution proposed by Lekhnitskii (1968) and Konish and Whitney (1975), widely used for orthotropic composite materials. When comparing the experimentally measured values with the analytical distributions of the strains, was observed little interference of the K values adopted to obtain the analytical curves, resulting in an agreement between the values obtained by the strain gages and the analytical model.Acesso AbertoMateriais compósitosTecidos multiaxiais acopladosPropriedades mecânicasFuro centralConcentração da deformaçãodoctoralThesisCNPQ::ENGENHARIAS::ENGENHARIA MECANICA