Fatigue Crack Nucleation
Mostrando 1-12 de 14 artigos, teses e dissertações.
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1. Influence of a Femtosecond Laser Surface Modification on the Fatigue Behavior of Ti-6Al-4V ELI Alloy
The objective of this investigation was to evaluate the influence of surface modification by femtosecond laser (with average fluence of 0.6 J/cm2 and scanning speed of 0.1 mm/s) on the fatigue resistance of Ti-6Al-4V ELI alloy. A significant reduction in the fatigue strength of the material modified by laser was observed. Residual tensile stresses generated
Mat. Res.. Publicado em: 01/07/2019
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2. Simulação do Processo de Soldagem Elétrica por Centelhamento de um Aço para Trilhos Ferroviários. Parte 1: Análise de Tensões Residuais Via Elementos Finitos
Resumo Trilhos longos, soldados pelo processo Flash Butt Welding (FBW), são a realidade das ferrovias brasileiras de média e alta carga por eixo. Embora apresentem características desejáveis do ponto de vista do comportamento dinâmico da via, as soldas são regiões de descontinuidade estrutural e mecânica onde se originam tensões residuais, e que est
Soldag. insp.. Publicado em: 27/06/2019
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3. Stress-based fatigue reliability analysis ofthe rail fastening spring clipunder traffic loads
Nowadays, the rail fastening systems play an important role for preserving the connection between the rails and sleepers in various conditions. In this paper, stress based concept is used to develop a comprehensive approach for fatigue reliability analysisof fastening spring clip. Axle load, speed and material properties are assumed to be random variables. F
Lat. Am. j. solids struct.. Publicado em: 2014-11
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4. Surface contact fatigue failure of a case hardened pinion shaft
An investigation was made to determine the causes of surface contact fatigue failure of a case hardened driver pinion located in the intermediate shaft of a reducer gearbox used in a sugar and alcohol mill. The examination of the component revealed the presence of a cemented layer substantially thicker than that generally specified for pinions devised for th
Mat. Res.. Publicado em: 20/05/2014
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5. Effect of salt-water fog on fatigue crack nucleation of Al and Al-Li alloys
Fatigue and corrosion-fatigue tests were performed to quantify the fatigue properties of AA2524-T3 and AA2198-T851 Al alloys. High cycle axial fatigue tests were carried out under air and salt-water fog conditions. In air, the specimens were fatigue tested at a frequency of 50 Hz, using specimens with and without preconditioning in a salt spray chamber, and
Mat. Res.. Publicado em: 26/11/2013
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6. Evaluation of fatigue strength at high temperature superalloy MAR-M247 (Nb) / Avaliação da resistência à fadiga em alta temperatura da superliga MAR-M247(Nb)
Este projeto faz parte de uma Rede Interdisciplinar de Pesquisa em Superligas no Brasil (Projeto Pró-Engenharias - CAPES), que tem como objetivo o desenvolvimento técnico e científico do Brasil nesta classe de materiais. A rede é composta por especialistas de estabelecida competência em assuntos fundamentais para o desenvolvimento de materiais estrutura
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/02/2012
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7. Estudo do efeito do ambiente no comportamento em fadiga de novas ligas \ AL\ de grau aeronáutico / Study of the effect of environment of the fatigue behavior of new \ AL\ alloys of aircraft grade
Ligas de alumínio que contém lítio são conhecidas por serem materiais atraentes devido à sua baixa densidade, alta elasticidade, alta resistencia mecânica e boa resistência à corrosão. A degradação do material devido à fadiga e corrosão são os dois principais fatores que contribuem para o envelhecimento de uma aeronave, e a previsão de corros�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/02/2011
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8. Avaliação do efeito do Mg nas propriedades de fadiga em alta temperatura de ligas de Al-Si fundidas sob pressão em molde permanente / Magnesium addition effect on high temperature fatigue properties of permanent mold cast Al-Si alloys
Gear Box housings are usually subjected to cyclic stresses generated during engine operation. Such stresses are more critical at high temperatures and long times. Thermal gradients induced within the components submitted to variation of temperature during working may result in internal stresses and strains. Thermal cycling can result in crack nucleation and
Publicado em: 2006
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9. Resistência à fadiga e comportamento em torção de instrumentos endodônticos de NiTi Profile
A comparative study of the torsion behavior and of the fatigue resistance of rotary NiTi endodontic instruments was performed in this work. ProFile 20/.04, 25/.04, 30/.04, 20/.06, 25/.06 e 30/.06 instruments were analyzed at the following conditions: Control Group 01, containing 10 non-used instruments of each size and taper, tested until rupture in fatigue
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/01/2004
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10. Fadiga térmica de ferros fundidos brancos multicomponentes. / Thermal fatigue of multicomponent white cast iron.
The effects of the volume fraction of eutectic carbides and of the matrix hardness on the thermal fatigue resistance of multicomponent white cast iron were investigated. Alloys Fe-4Cr-V-2Mo-2W-2C, V ranging from 5 to 8 wt% and Fe-4Cr-8V-Mo-2W-2C, Mo ranging from 2 to 5 wt % were used. Disc shaped samples were quench and tempered for obtaining two matrix micr
Publicado em: 2003
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11. Estimation of the Plain High-Cycle Fatigue Propagation Resistance in Steels
In this work a method to estimate the high cyclic fatigue propagation life of steel specimens under constant loading is presented. This method is based in experimental evidence that the fatigue limit represents the threshold stress for the propagation of nucleated cracks, so that both the fatigue limit and the fatigue resistance depend on the effective resis
Materials Research. Publicado em: 2002-06
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12. The effect of surface rolling on fatigue behavior in a pearlitic ductile cast iron / "Influência do roleteamento no comportamento em fadiga de um ferro fundido nodular perlítico"
Surface rolling is a mechanical treatment commonly used in parts fabricated with steel and ductile cast iron, specifically in stress concentration regions, to improve fatigue properties. This process hardens and introduces compressive residual stresses to the surface of the material through the application of controlled strains, thus provoking a reduction of
Publicado em: 2002