Metodologia de análise de fadiga em componentes estruturais de aço baseada na mecânica da fratura.

• Ano de defesa: 2004
• Autor(a) principal: Ricardo Santos Teixeira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Propagação de trincas; Fadiga; Mecânica da fratura; Estruturas de aço; Fator de intensidade de tensão; Engenharia de estruturas; Aço Estruturas; Aço Fadiga; Mecanica da fratura
• Link de acesso: http://hdl.handle.net/1843/FACO-6AYH8B

The fatigue analysis of steel structural members containing defects under the action of variable loads is the main objective of this work. For this purpose, a bibliographical research has been performed to find the most common defects like cracks in steel structures. The conclusion from this research is that this type of defects has been mainlyobserved in welded joints. The fatigue analysis of components with defects has been developed through an approach based on Fracture Mechanics. This approach is the most realistic and modern to deal with this kind of analysis. Further this; fatigue analysis is one of the most successful applications of Fracture Mechanics. The evaluation of thestress intensity factor, KI, in the analysis of the fatigue life, is particularly cumbersome in three-dimensional problems with complex geometries, and sometimes is possible only by using numerical methods. An extensive bibliographical research has been developed, as well as an intense testing program to validate a methodology for the analysis of cracks propagation and fatigue life evaluation, based on numerical methods and Fracture Mechanics concepts. In order to calculate the stress intense factor KI in structural members containing defects, the computational program FRANC3D, based on the boundary elements method, has been applied. From the results obtained for KI, thefatigue life was calculated for a simple supported steel I shaped beam supporting a runway crane, subjected to cyclic loads. It was assumed the occurrence of two types of the most common defects in the in web-to-flange junction of the beam. The results of fatigue life obtained in this way are of the same magnitude order of those evaluated byusing the simplified procedures adopted by the NBR 8800 code for structural steel.