Stress Intensity Factor
Mostrando 25-36 de 41 artigos, teses e dissertações.
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25. Characteristics of the double-torsion test to determine the R-curve of ceramic materials
Double-torsion tests were carried out on a commercial ceramic floor tile to verify whether this test is suitable for determining the R-curve of ceramics. The instantaneous crack length was obtained by means of compliance calibration, and it was found that the experimental compliance underestimates the real crack length. The load vs. displacement curves were
Materials Research. Publicado em: 2006-12
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26. THE STRUCTURAL BEHAVIOUR OF COMPOSITE LAMINATES MANUFACTURED USING RESIN INFUSION UNDER FLEXIBLE TOOLING
This thesis presents a detailed investigation on the structural behaviour of hybrid plain weave composite laminates manufactured using Resin Infusion under Flexible Tooling (RIFT) process under static and dynamic impact loading conditions. Composite laminates were manufactured using a newly developed RIFT manufacturing facility marking the beginning of a new
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 200511
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27. Humor e estresse no trabalho: fatores psicossociais estressores e benéficos no trabalho dos operadores de telemarketing / Humor and stress at work: psychosocial stressors and protecting factors at work of telemarketers
Aim. Taking into account the two-dimensional nature of stress-related psychosocial factors (CASSEL, 1974), the study aimed at identifying the interrelation of negative (stressors) and protecting (beneficial) such factors in the work of a group of telemarketing operators, and the potential of humor as a \ psychosocial resource\ in face of stress at work, as a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/05/2005
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28. Metodologia de análise de fadiga em componentes estruturais de aço baseada na mecânica da fratura.
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 mainly observed in w
Publicado em: 2004
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29. Heat storage rate and acute fatigue in rats
Thermal environmental stress can anticipate acute fatigue during exercise at a fixed intensity (%VO2max). Controversy exists about whether this anticipation is caused by the absolute internal temperature (Tint, ºC), by the heat storage rate (HSR, cal/min) or by both mechanisms. The aim of the present study was to study acute fatigue (total exercise time, TE
Brazilian Journal of Medical and Biological Research. Publicado em: 2003-01
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30. Modeling fatigue crack opening and closing phenomenon by finite element method. / Modelamento do fenômeno de abertura e fechamento de trincas em fadiga pelo método dos elementos finitos.
O trabalho apresenta uma metodologia para a simulação de abertura e fechamento de trinca, durante o processo de propagação, utilizando um programa comercial de elementos finitos. Este programa é utilizado para determinar os fatores de intensidade de tensão de abertura e fechamento de trinca. É apresentado o modelo de Newman que serve de embasamento pa
Publicado em: 2003
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31. A variação da acuidade visual durante esforços fisicos em atletas com baixa visão
This research work evaluated the response of the visual acuity in visually impaired athletes during a procedure of continued physical exercise. The evaluation was carried out in two days of testing. The subjects were six visually impaired, high performance runners athletes. The following were carried out during the first day: medical examination, anamnesis a
Publicado em: 2002
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32. Modelagem semi-analitica pseudo tridimensional de propagação e fechamento de fraturas induzidas em rochas
This investigation describes a semi-analytical model which simulates fracture propagation in petroleum reservoir rocks. The model permits evaluating the three fracture dimensions parameters (width, height and length) during propagation. Like other pseudo 3D models, some assumptions are used to solve the fracture three-dimensional propagation problem, such as
Publicado em: 1998
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33. Solução de problemas poroelasticos atraves do metodo dos elementos de contorno
The Biot s theory af poroelasticity is revisited making it more easily applicable to practical problems. The parameters used by Biot are redefined as functions of other ones with an easier and simpler physical interpretation. This helps their determination and the understanding of poroelastic phenomena. The equations that govern the theory of quasi-static li
Publicado em: 1995
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34. Obtenção do fator de intensidade de tensão pelo método da função de green local modificado
The stress intensity factor is of paramount importance at failure analysis, fatigue and fracture mechanics, this methodology is used when the cost is high and the safety essential. In this way, a lot of methods have been used and, among of them, one has the Finite Element and the Boundary Element methods, the first needs a fine mesh getting a high computatio
Publicado em: 1993
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35. Anisotropias induzidas em ligas ferromagnéticas amorfas / Induced anisotropy in amorphous ferromagnetic alloys
In this thesis we will present a series of studies related to induced magnetic anisotropies (Kind) in amorphous alloys. In order to get a more general view of this theme, we used several different kinds of annealings. The theoretical analysis of the data of Kind and magnetic after-effect (MAE) was performed using a model based on two-level systems (TLS). Fro
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/03/1991
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36. Deficient induction of human hsp70 heat shock gene transcription in Y79 retinoblastoma cells despite activation of heat shock factor 1.
One of the basic features of the inducible heat shock response is the activation of heat shock factor which results in the rapid transcriptional induction of the heat shock genes. Although it is widely considered that the heat shock response is ubiquitous, several reports have indicated that the transcriptional response can vary in both intensity and kinetic