Medidas de tensões residuais por extensometria em componentes usados no setor da mobilidade

Abstract

Many engineering specifications, manufacturing procedures, inspection and quality controls have begun to require that the residual stress analysis of a particular component is evaluated. This is becoming as common place as the demands on the mechanical properties. In the country there are few research laboratories qualified to perform these tests and also found a disturbing lack of skilled labor. The relevance of the study and research on residual stresses, stresses the development of science, technology and innovation in manufacturing components for the industry. New tools and instrumentation for the investigation of microstructure of materials available in research laboratories both in governmental institutions such as private facilities in need of qualified researchers which is associated with the training of specialists dedicated to measurements of residual stresses, the development of experimental procedures and sample preparation techniques involving gages. The residual stress in metal and alloy components arises as a result of manufacturing processes (casting, heat treatment, machining and mechanical forming) by which to obtain the structural form of the desired component. Study the formation and arrangement of residual stress fields may allow, among other gains, the development of mathematical modeling simulations more refined. Thus it can be inferred, in more detail the behavior of these components by adding gains in resilience to fatigue, survival, security and operational cost reduction of equipment and machinery. The use of strain gage in the investigation of residual stresses in automotive wheels contribute to the formation of a larger database that will allow for FEM simulation software, with a better index of mathematical modeling with respect to the real physical component. vii LISTA DE SIGLAS a; aₒ , ac Comprimentos da amostra b Dimensão da amostra B Espessura da amostra C Constante de material D Dimensão do círculo preenchendo um defeito e Flexibilidade ep ; eq Deformações principais h Altura hp Zona plástica K Constante de barreiras microestruturais k' Parâmetro determinado por elementos finitos K Fator de intensidade de tensão K Constante do material Kres Fator de intensidade de tensão no campo de tensões residuais Ko Limiar do fator de intensidade de tensão Kg Constante de material K Fator de concentração de deformação inelástica L Comprimento da trinca