EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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3 resultados
Resultados da Pesquisa
Item Statistical modeling of fatigue crack growth rate in pre-strained 7475-T7351 aluminum alloy.(2008) Al-Rubaie, Kassim Shamil Fadhil; Barroso, Emerson Kellem Lana; Godefroid, Leonardo BarbosaIn this study, 7475-T7351 aluminum strips were subjected to two tensile pre-strain levels of 3% and 5%. Using compact tension C(T) specimens, fatigue crack growth tests were conducted under constant amplitude loading at stress ratios of 0.1 and 0.5 in air and at room temperature. Three fatigue crack growth rate (FCGR) models, namely, Collipriest, Priddle, and NASGRO were examined. To handle the effect of stress ratio on FCGR, Walker equivalent stress intensity factor model was used. Consequently, generalized Collipriest (GC), generalized Priddle (GP), and generalized NASGRO (GN) models were developed and fitted to the FCGR data. It was shown that both GC and GP models fit the FCGR data in a similar fashion. However, the GP model provided a better fit than the GC model. The GN model was found to be the most appropriate model for the data. Therefore, this model may be suggested for use in critical applications, such as aeronautical structural design.Item Statistical modeling of fatigue crack growth rate in Inconel alloy 600.(2007) Al-Rubaie, Kassim Shamil Fadhil; Godefroid, Leonardo Barbosa; Lopes, Jadir Antônio MoreiraInconel alloy 600 is widely used in heat-treating industry, in chemical and food processing, in aeronautical industry, and in nuclear engineering. In this work, fatigue crack growth rate (FCGR) was evaluated in air and at room temperature under constant amplitude loading at a stress ratio of 0.1, using compact tension specimens. Collipriest and Priddle FCGR models were proposed to model the data. In addition, these models were modified to obtain a better fit to the data, especially in the near-threshold region. Akaike information criterion was used to select the candidate model that best approximates the real process given the data. The results showed that both Collipriest and Priddle models fit the FCGR data in a similar fashion. However, the Priddle model provided better fit than the Collipriest model. The modified Priddle model was found to be the most appropriate model for the data.Item Fatigue crack growth analysis of pre-strained 7475–T7351 aluminum alloy.(2006) Al-Rubaie, Kassim Shamil Fadhil; Barroso, Emerson Kellem Lana; Godefroid, Leonardo BarbosaAluminum alloys are widely used in aeronautical design due to their good mechanical properties and low densities. Among these alloys, 7475 (Al–Zn–Mg–Cu), modified from 7075, is successfully used due to strength similar to that of 7075 and superior fracture toughness. In this study, strips of 7475–T7351 were subjected to two tensile pre-strain levels of 3 and 5%. Using compact tension C(T) specimens, fatigue crack growth (FCG) tests were conducted in air under constant amplitude loading at a stress ratio of 0.5. Three FCG rate models, namely Collipriest, Priddle, and modified Forman were examined. The results showed that both fracture toughness and FCG resistance decreased with an increase in the prestrain level. Both Collipriest and Priddle models fit the FCG rate data in a similar fashion. However, the Priddle model provided a better fit than Collipriest. The modified Forman model provided the best fit to the FCG rate data as compared with the other two models. The modified Forman model used to fit other unpublished FCG data and its response was also superior to the others. Therefore, this model may be suggested for use in critical applications, such as aeronautical structural design.