Análise da propagação de trinca por fadiga submetida a carregamento cíclico com razão de carga negativa para a liga AA 6005

• Autor(a) principal: Silva, Bárbara Rezende Leite [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/156945; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2018-08-28/000906177.pdf
• topic: Mecânica da fratura; Ligas de aluminio; Fadiga; Fracture mechanics

For engineering projects requiring a high degree of reliability, it is necessary to understand, in addition to the physical and chemical properties of the materials, its limits for static and dynamic applications, in order to guarantee structural integrity and safety. The Fadiga study is a project item of great importance. Fatigue life comprises nucleation and the propagation of cracks, and most of life can be consumed during propagation. Many models and theories have been proposed in order to understand and predict the crack propagation behavior in fatigue. In this context, fatigue cracking propagation involving loading with negative R has generated discussions and controversies about the influence of the compressive load as a driving force in the crack propagation. Some researchers assume that the compressive part of the cyclic loading has no influence on the crack growth. In addition, the industry is increasingly using aluminum alloys in its projects. AA 6005 series alloys have good fatigue, corrosion and weldability. They are applied in railway and bus structures, structural engineering, towers, platforms and pipelines. In this work, fatigue crack propagation tests were performed on specimens with initial central pre-crack for R = -1 and R = 0 for the same maximum loads on the AA6005 aluminum alloy. The results showed that the negative part of the load influenced the propagation rate of the fatigue crack, mainly for larger cracks sizes and smaller loads