Análise de critérios de falha em lâmina reforçada com tecido híbrido de fibra de vidro e carbono

The constant search for more efficient materials and with high mechanical performance, contributes effectively to the growing demand in the use of hybrid composites. The hybridization process can provide significant improvement in the overall combination of properties, thus enabling specific applica...

ver descrição completa

Na minha lista:
Detalhes bibliográficos
Autor principal: Campos, Virginia Bezerra Oliveira
Outros Autores: Freire Júnior, Raimundo Carlos Silverio
Formato: Dissertação
Idioma:por
Publicado em: Brasil
Assuntos:
Endereço do item:https://repositorio.ufrn.br/jspui/handle/123456789/24556
Tags: Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
Descrição
Resumo:The constant search for more efficient materials and with high mechanical performance, contributes effectively to the growing demand in the use of hybrid composites. The hybridization process can provide significant improvement in the overall combination of properties, thus enabling specific applications in structural elements that require excellence in their mechanical properties and low specific mass. Coupled with the gradual use of these materials, studies that focus on fault predictions and, consequently, analyzes of the maximum loads that these materials can withstand become essential to guarantee the reliability of their application. In this sense, the present research sought to analyze the mechanical behavior of laminae composed of two-way hybrid fabric (glass/carbon) and epoxy resin vinyl ester. As well as evaluating the representativeness of failure criteria developed for unidirectional composites when applied in hybrid composites of a bidirectional nature. The laminas studied were mechanically characterized based on the results obtained by tensile and shear tests performed on samples with carbon fibers orientated at 0°, 30°, 45°, 60° and 90°. It was observed from these tests that materials with fibers at off-axis loading angles exhibit lower strength, although they exhibit greater elongations when compared to samples with fibers aligned in the main direction of loading. Experimental data on shear properties, standardized by ASTM D3518M-13 (tensile shear test ±45°) and ASTM D5379-12 (Iosipescu's test), showed significant differences for shear strength and similarity in the modulus values of Shear. The tensile test ± 45°, according to macromechanical analysis, proved to be the most suitable for composite with characteristics similar to the one analyzed. By inserting test data into the theoretical equations defining Tsai-Hill, Tsai-Wu, and Hashin fault criteria, and statistically analyzing them, it was found that these fault theories satisfactorily describe the experimental behavior of the blade , and therefore can be used to predict mechanical strength in composites as evaluated, although higher representativity indices were observed when using the ± 45° traction shear test.