Author: J. Heerens
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description

Author: Jürgen Heerens
Publisher:
ISBN:
Category : Pressure vessels
Languages : en
Pages : 39

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Book Description

Author: J. M. INGRAHAM
Publisher:
ISBN:
Category :
Languages : en
Pages : 1

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Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Fracture properties of Reactor Pressure Vessel (RPV) steels show large variations with changes in temperature and irradiation levels. Brittle behavior is observed at lower temperatures and/or higher irradiation levels whereas ductile mode of failure is predominant at higher temperatures and/or lower irradiation levels. In addition to such temperature and radiation dependent fracture behavior, significant scatter in fracture toughness has also been observed. As a consequence of such variability in fracture behavior, accurate estimates of fracture properties of RPV steels are of utmost importance for safe and reliable operation of reactor pressure vessels. A cohesive zone based approach is being pursued in the present study where an attempt is made to obtain a unified law capturing both stable crack growth (ductile fracture) and unstable failure (cleavage fracture). The parameters of the constitutive model are dependent on both temperature and failure probability. The effect of irradiation has not been considered in the present study. The use of such a cohesive zone based approach would allow the modeling of explicit crack growth at both stable and unstable regimes of fracture. Also it would provide the possibility to incorporate more physical lower length scale models to predict DBT. Such a multi-scale approach would significantly improve the predictive capabilities of the model, which is still largely empirical.

Author: SM. Graham
Publisher:
ISBN:
Category : Bruchmechanik
Languages : en
Pages : 23

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Book Description
The dynamic fracture toughness of an ASTM A533, Grade B steel plate was determined at several temperatures in the ductile-brittle transition region. Crack-tip loading rates ranged from approximately 103 to 105 MPa?m/s. The fracture toughness was shown to decrease with increased loading rate. The dynamic fracture toughness was compared with results from previous investigations and it was shown that the decrease in toughness due to increased loading rate at the highest test temperature was not as severe as reported in previous investigations. It was also shown that the reference temperature, T0, was a better index of the fracture toughness vs. temperature relationship than the nil-ductility temperature, RTNDT for this material.

Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 476

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Book Description
Reports NIST research and development in the physical and engineering sciences in which the Institute is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Emphasis on measurement methodology and the basic technology underlying standardization.

Author: John D. Landes
Publisher: ASTM International
ISBN: 0803119909
Category : Electronic book
Languages : en
Pages : 805

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Book Description

Author: MR. Goldthorpe
Publisher:
ISBN:
Category : Biaxial wide plate tests
Languages : en
Pages : 23

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Book Description
A method of analyzing the ductile to brittle transition region of a ferritic steel using a coupled micromechanical model of ductile damage, stable crack growth and cleavage fracture has been developed to improve the definition of upper shelf behavior for actual structures. Ductile damage is modelled using the Gurson model as modified by Tvergaard, along with a specially developed crack growth user element. The probability of cleavage fracture is predicted by post-processing the finite element results using the Beremin model of cleavage fracture. Predictions are made of ductile tearing and cleavage fracture in test specimen and wide plate configurations of A533B steel for a range of temperatures. The coupled model is capable of predicting transition toughness and transition temperature shifts for different levels of structural constraint. An analytically-based definition of the onset of upper shelf temperature (OUST) is the temperature at which the coupled ductile damage/cleavage fracture model predicts a probability of failure by cleavage fracture of 5%. Estimates of the shift in the OUST due to different levels of in-plane crack tip constraint are made using the elastic T-stress as a measure of constraint. There is potential for using the T-stress as a measure of structural constraint in order to determine shifts in transition temperature for materials with degraded toughness.

Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 48

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Book Description
The bibliography has been compiled from the unclassified literature for the period January 1950 through November 15, 1961. Reviews and bibliographies which have been listed furnish references to historical reviews and earlier studies on brittle fracture. An author and a subject index are included.

Author: Ted L. Anderson
Publisher: CRC Press
ISBN: 9780849342608
Category : Science
Languages : en
Pages : 1148

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Book Description
This bestselling text/reference provides a comprehensive treatment of the fundamentals of fracture mechanics. It presents theoretical background as well as practical applications, and it integrates materials science with solid mechanics. In the Second Edition, about 30% of the material has been updated and expanded; new technology is discussed, and feedback from users of the first edition has been incorporated.