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Abstract(s)
O uso de materiais compósitos tem cada vez mais assumido um papel de maior grandeza com o passar dos tempos, a investigação e a aplicação destes materiais tem aumentado. Em conjunto com o desenvolvimento destes materiais e a preocupação crescente com o meio ambiente, surge a necessidade de aproveitamento de resíduos para o fabrico de compósitos, as vantagens para o meio ambiente e custo final de produção são notórias. Tendo em conta que a produção de materiais compósito é realizada maior parte das vezes com o intuito de obter produtos sob a forma final, surge então um problema a quando da maquinagem dos mesmo. Devido à sua composição a maquinagem dos mesmos nem sempre é viável pois insurge defeitos na peça, quando o processo de ligação entre duas peças é necessariamente mecânico, o processo de maquinagem torna-se impossível de contornar em maior parte dos casos. Com as duas premissas anteriores em conta, surgem os objetivos deste estudo. O primeiro objetivo consiste na compreensão e tentativa de previsão de influências e propriedades, induzidas em materiais compósitos com a adição de cargas na matriz. O segundo consiste na análise da influência, negativa ou positiva dessa mesma adição de cargas em relação ao processo de Furação. Foram então testadas 48 placas de materiais compósitos com reforços de fibras de vidro e fibras de carbono, todas com diferentes composições em relação a matriz e empilhamento. Essas placas foram todas furadas e maquinadas sempre sob os mesmos parâmetros, com o intuito de descobrir a influencia da alteração de composição nas propriedades dos laminados. Através da definição de amostras padrão, foram estabelecidos conjuntos de provetes com base na carga presente em cada matriz e percentagem volúmica da mesma. A composição destes conjuntos permitiu então concluir sobre a alteração gerada pelas cargas nas propriedades dos compósitos e provetes furados.
The use of composite materials has taken on a greater role over time, the research and application of these materials has increased. The development of these materials together with the growing concern with the environment, appears a need for using recovered waste in the manufacture of composites, the advantages for the environment and the final cost of production are notorious. Bearing in mind that the production of composite materials is carried out most of the time in order to obtain products in the final form, a problem then arises when machining them. Due to their composition, their machining is not always viable because it causes defects on parts, when the connection process between two parts is necessarily mechanical, the machining process becomes important in most cases. With the two previous sentences in mind, the objectives of this study emerge. The first objective is to understand and try to predict influences and properties, induced in composite materials with the addition of fillers in the matrix. The second consists in the analysis of the influence, negative or positive, of this same load addition in relation to the drilling process. 48 plates of composite materials were then tested, with glass fiber and carbon fiber reinforcements and all with different compositions of matrix and stacking. These plates were all drilled and machined, always under the same parameters, in order to discover the influence of the composition change on the properties of the laminates. Through the definition of standard samples, sets of specimens were established based on the load presented in each matrix and its volume percentage. The composition of these sets allowed us to conclude about the change generated by the loads in the properties of the composites and pierced test pieces.
The use of composite materials has taken on a greater role over time, the research and application of these materials has increased. The development of these materials together with the growing concern with the environment, appears a need for using recovered waste in the manufacture of composites, the advantages for the environment and the final cost of production are notorious. Bearing in mind that the production of composite materials is carried out most of the time in order to obtain products in the final form, a problem then arises when machining them. Due to their composition, their machining is not always viable because it causes defects on parts, when the connection process between two parts is necessarily mechanical, the machining process becomes important in most cases. With the two previous sentences in mind, the objectives of this study emerge. The first objective is to understand and try to predict influences and properties, induced in composite materials with the addition of fillers in the matrix. The second consists in the analysis of the influence, negative or positive, of this same load addition in relation to the drilling process. 48 plates of composite materials were then tested, with glass fiber and carbon fiber reinforcements and all with different compositions of matrix and stacking. These plates were all drilled and machined, always under the same parameters, in order to discover the influence of the composition change on the properties of the laminates. Through the definition of standard samples, sets of specimens were established based on the load presented in each matrix and its volume percentage. The composition of these sets allowed us to conclude about the change generated by the loads in the properties of the composites and pierced test pieces.
Description
Keywords
Compósitos com matriz termoendurecível Valorização de resíduos Maquinagem Propriedades mecânicas Forças axiais na furação Análise da composição Thermosetting matrix composites Waste recovery, Machining Mechanical properties Axial forces in drilling Analysis of compositions