Fracture Criterion
Mostrando 13-24 de 24 artigos, teses e dissertações.
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13. High bone mineral density in postmenopausal women: determinant factors / Densidade mineral óssea alta em mulheres na pós menopausa: fatores determinantes
The concept of high bone mineral density (HBMD) is controversial and different values of BMD have been considered as threshold for this classification. Whereas HBMD may be present in normal and abnormal, it is important to analyze the possible factors determining this clinical condition. We studied 337 postmenopausal women (180 with HBMD and 157 control grou
Publicado em: 2009
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14. An adaptive strategy for elastic-plastic analysis of structures with cracks
This work presents a methodology for self-adaptive finite element analysis of two-dimensional elastic-plastic structures. The self-adaptive process is based on an h-type refinement, with a posteriori error estimation. Two types of error estimators are available. The first is based on effective stress (Lee and Bathe, 1994) and the second is based on a ratio o
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2008-12
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15. Trends in the prevalence of traumatic dental injuries in Brazilian preschool children / Estudo da tendência das lesões dentárias traumáticas em crianças de 5 a 59 meses de idade. Diadema - São Paulo
Traumatic dental injuries (TDI) present high prevalence in many countries. Epidemiological studies on TDI are important to determine the disease prevalence and to establish oral health promotion strategies. No study in the literature shows trend in TDI in primary dentition. The aim of this study was: 1) To determine the prevalence and distribution of TDI in
Publicado em: 2008
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16. STRUCTURAL ASSESSMENT OF PIPELINES WITH BLUNT CORROSION DEFECTS COINCIDENT WITH LONG-SEAM WELDS / AVALIAÇÃO ESTRUTURAL DE DUTOS COM DEFEITOS DE CORROSÃO COINCIDENTES COM A SOLDA LONGITUDINAL
One of the most important issues that affects pipeline integrity is corrosion-caused metal loss. This type of defect can occur over the pipe body, seam or girth welds or even on heat affected zones. Pipeline remaining strength criterions are restricted or even prohibited for assessing corrosion defects coincident with weld regions. This present work investig
Publicado em: 2007
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17. Avaliação numérico-experimental da fratura dúctil em processos predominantementetrativos e compressivos
Failure prediction in fracture-free materials under a general stress-strain path has posed a great challenge to researchers. Despite the fact that numerical assessment of ductile failure under tensile stress states has been reasonably well described in the literature, a definition of a failure criterion or modelling approach capable to successfully predict f
Publicado em: 2006
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18. Ultra-sonometria óssea para determinação do risco de fratura do fêmur / Bone ultra-sonometry for the assesment of the fêmur fracture risk
Osteoporosis is a disease which affects the bone tissue reducing its resistance that is determined by its density, architecture and speed of remodeling. Currently, the pattern method used for its diagnosis and monitoring is the bone densitometry which makes use of ionizing radiation and because of its high costs, it is not available to the majority of the lo
Publicado em: 2006
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19. Resistência à fratura de raízes fragilizadas restauradas com resina composta e pinos de fibra de vidro submetidas à ciclagem mecânica / Resistance to fracture of weakened roots restored with composite resin and glass fiber post submitted to cyclic loading
The preservation and restoration of severely weakened pulpless teeth is a difficult and unpredictable procedure. This study evaluated the resistance to fracture and fracture patterns of weakened roots after restoration with glass fiber post, filling core of composite resin and total metallic crown submitted to cyclical and compressive load. Thirty upper cani
Publicado em: 2005
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20. Finite element-based model for crack propagation in polycrystalline materials
In this paper, we use an extended form of the finite element method to study failure in polycrystalline microstructures. Quasi-static crack propagation is conducted using the extended finite element method (X-FEM) and microstructures are simulated using a kinetic Monte Carlo Potts algorithm. In the X-FEM, the framework of partition of unity is used to enrich
Computational & Applied Mathematics. Publicado em: 2004-12
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21. Numerical investigation of constraint effects on ductile fracture in tensile specimens
This study explores the capabilities of a computational cell framework into a 3-D setting to model ductile fracture behavior in tensile specimens. The cell methodology provides a convenient approach for ductile crack extension suitable for large scale numerical analyses which includes a damage criterion and a microstructural length scale over which damage oc
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-06
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22. Mezzo-scopic Analysis of Fracture Toughness in Steels
The cleavage fracture toughness of steels was mezzo-scopically analyzed on the basis of the statistical local fracture criterion approach. The statistical stress criterion at the crack tip region suggests that the cleavage fracture toughness in steels can be described as a function of the yield stress, the cleavage fracture stress, and other mechanical prope
Materials Research. Publicado em: 2002-06
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23. Um modelo quase-analitico para simulação tridimensional de propagação de fratura hidraulica
Several models for the development of a fully three-dimensional hydraulic fracturing simulator have been described in the literature. However, most of them result in systems that require computational efforts not compatible with the direct application in the field. In order to attenuate this problem, simplified assumptions are introduced, resulting in pseudo
Publicado em: 1996
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24. Fracture dynamics of fusion of two anti-plane cracks
The problem of the fracture dynamics of two two-dimensional coplanar anti-plane shear cracks is considered. Both cracks extend under a critical stress-intensity fracture criterion. The two cracks are initiated at different locations and times. A solution developed by Kostrov [Kostrov, B. V. (1966) J. Appl. Math. Mech. 30, 1241-1248] for isolated cracks is us