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Abstract(s)
O comportamento das juntas coladas quando sujeitas ao impacto tem recebido pouca atenção por parte da comunidade cientĂfica. Visto que elas sĂŁo a forma mais eficiente de ligar componentes/estruturas feitas em materiais compĂłsitos e que, por sua vez, estes materiais tĂȘm vindo a ganhar terreno nas diversas ĂĄreas da engenharia, nomeadamente a aeronĂĄutica, torna-se necessĂĄrio aprofundar os conhecimentos neste domĂnio. Na verdade, sĂŁo inevitĂĄveis os choques com aves ou a simples queda de uma ferramenta e, deste modo, a aeronavegabilidade da estrutura pode ficar seriamente comprometida.
Os efeitos estudados ao longo deste trabalho, adotando uma geometria com um laminado a reforçar, foram a espessura e o comprimento desse mesmo laminado e, ainda, o comprimento do gap. Variando esses parĂąmetros, foram efetuados diferentes ensaios ao impacto a diferentes energias. Foi possĂvel tirar algumas conclusĂ”es no que concerne ao melhor desempenho ao impacto. Assim, as configuraçÔes mais resistentes dentro dos intervalos estudados, foram obtidos para a maior espessura (4,5 mm), maior comprimento (60 mm) e maior comprimento do gap (20 mm). Para alĂ©m disso, tambĂ©m se obtiveram resultados no que toca Ă força e deslocamento mĂĄximos, bem como a energia absorvida e a rigidez Ă flexĂŁo, sendo que os melhores valores destes nĂŁo se prendem, necessariamente, com os provetes que melhor performance ao impacto tiveram.
The behavior of adhesive joints when subjected to the impact has received little attention. Adhesive joints are the most efficient way of connecting parts made of composite materials. Since the use of these materials have been increasing in the most varied areas of engineering, especially aeronautical engineering, it is necessary to deepen the knowledge about this theme. Several components of an aircraft are subject to impacts, whether low or high-velocity impacts. For example, bird strikes or a simple tool drop can trigger catastrophic failures that compromise the airworthiness of the whole structure. The effects studied throughout this work, adopting a simple geometry with an overlay laminate were the thickness and the length of that laminate and also the gap length. By varying these parameters, different tests using different impact energies were executed. It was possible to draw some conclusions regarding the best performance to impact. Therefore, the better configurations, responding to impact, within the ranges studied, were obtained for the thicker laminate (4.5 mm), the laminate with the largest length (60 mm) and the largest gap length (20 mm). Furthermore, there were also other results obtained regarding the maximum force and displacement as well as the absorbed energy and impact bending stiffness. The best values for these do not relate necessarily to the samples which had the best performance to impact.
The behavior of adhesive joints when subjected to the impact has received little attention. Adhesive joints are the most efficient way of connecting parts made of composite materials. Since the use of these materials have been increasing in the most varied areas of engineering, especially aeronautical engineering, it is necessary to deepen the knowledge about this theme. Several components of an aircraft are subject to impacts, whether low or high-velocity impacts. For example, bird strikes or a simple tool drop can trigger catastrophic failures that compromise the airworthiness of the whole structure. The effects studied throughout this work, adopting a simple geometry with an overlay laminate were the thickness and the length of that laminate and also the gap length. By varying these parameters, different tests using different impact energies were executed. It was possible to draw some conclusions regarding the best performance to impact. Therefore, the better configurations, responding to impact, within the ranges studied, were obtained for the thicker laminate (4.5 mm), the laminate with the largest length (60 mm) and the largest gap length (20 mm). Furthermore, there were also other results obtained regarding the maximum force and displacement as well as the absorbed energy and impact bending stiffness. The best values for these do not relate necessarily to the samples which had the best performance to impact.
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Keywords
Impacto de Baixa Velocidade Juntas Coladas Materiais CompĂłsitos