Assessing the Loading Rate for a Fracture Toughness Test in the Ductile-to-Brittle Transition Region

Assessing the Loading Rate for a Fracture Toughness Test in the Ductile-to-Brittle Transition Region PDF Author: Enrico Lucon
Publisher:
ISBN:
Category : Ductile iron
Languages : en
Pages : 12

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Book Description
For fracture toughness tests in the ductile-to-brittle transition region, ASTM E1921-05 requires specimens to be loaded using a loading rate dK/dt between 0.1 and 2 MPa?m/s during the initial elastic portion. It has been proposed that the standard allow testing at higher loading rates, including precracked Charpy specimens tested on an instrumented pendulum machine (impact toughness tests). The revised standard would require test results (KJc or To) to be reported along with the relevant loading rate, and should therefore provide guidance on how to assess the value of dK/dt in a relatively simple but reliable manner. Various options for measuring the loading rate have been investigated in this paper for several fracture toughness tests performed at different loading rates (quasi-static, dynamic, and impact). For each loading rate, three different toughness levels have been considered: low, medium, and high. Three considerably different materials have been selected: two RPV steels (JRQ, JSPS) and a ferritic/martensitic 9 % chromium steel (EUROFER97). It is found that the preferable option is given by the ratio between KJc and time at the onset of cleavage, whereas the elastic value Kel/tel or the average dK/dt can be used when partial unloadings are performed.

Assessing the Loading Rate for a Fracture Toughness Test in the Ductile-to-Brittle Transition Region

Assessing the Loading Rate for a Fracture Toughness Test in the Ductile-to-Brittle Transition Region PDF Author: Enrico Lucon
Publisher:
ISBN:
Category : Ductile iron
Languages : en
Pages : 12

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Book Description
For fracture toughness tests in the ductile-to-brittle transition region, ASTM E1921-05 requires specimens to be loaded using a loading rate dK/dt between 0.1 and 2 MPa?m/s during the initial elastic portion. It has been proposed that the standard allow testing at higher loading rates, including precracked Charpy specimens tested on an instrumented pendulum machine (impact toughness tests). The revised standard would require test results (KJc or To) to be reported along with the relevant loading rate, and should therefore provide guidance on how to assess the value of dK/dt in a relatively simple but reliable manner. Various options for measuring the loading rate have been investigated in this paper for several fracture toughness tests performed at different loading rates (quasi-static, dynamic, and impact). For each loading rate, three different toughness levels have been considered: low, medium, and high. Three considerably different materials have been selected: two RPV steels (JRQ, JSPS) and a ferritic/martensitic 9 % chromium steel (EUROFER97). It is found that the preferable option is given by the ratio between KJc and time at the onset of cleavage, whereas the elastic value Kel/tel or the average dK/dt can be used when partial unloadings are performed.

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 464

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Fracture Mechanics

Fracture Mechanics PDF Author: Ravinder Chona
Publisher: ASTM International
ISBN: 0803118678
Category : Electronic book
Languages : en
Pages : 864

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Book Description
The proceedings of the 23rd National Symposium on Fracture Mechanics, held in College Station, Texas, June 1991, present a broad overview of the current state of the art in fracture mechanics research. Following the Swerdlow Lecture (Structural Problems in Search of Fracture Mechanics Solutions by

Statistical Field Theories

Statistical Field Theories PDF Author: Andrea Cappelli
Publisher: Springer Science & Business Media
ISBN: 9781402007606
Category : Science
Languages : en
Pages : 392

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Book Description
Recent developments in theoretical physics include new instances of the unification of quite different phenomena. The theoretical community is challenged by the growing interactions between high-energy physics, statistical physics, and condensed matter physics. The common language, though, is exact solutions of two-dimensional and conformable field theories. This volume is a faithful representation of this interdisciplinary domain. Conformable and integrable field theories have been active research topics for several decades. The main recent developments concern the boundary effects and applications to disordered systems. The number of applications of the exact methods to condensed-matter problems has been growing over the years. Nowadays it is widely recognized that strongly interacting systems in low dimensions can be successfully described by integrable and conformable theories. This volume is an indispensable aid to those seeking to find their way in this domain.

Invariant Probabilities of Markov-Feller Operators and Their Supports

Invariant Probabilities of Markov-Feller Operators and Their Supports PDF Author: Radu Zaharopol
Publisher: Springer Science & Business Media
ISBN: 9783764371340
Category : Mathematics
Languages : en
Pages : 1008

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Book Description
This book covers invariant probabilities for a large class of discrete-time homogeneous Markov processes known as Feller processes. These Feller processes appear in the study of iterated function systems with probabilities, convolution operators, and certain time series. From the reviews: "A very useful reference for researchers wishing to enter the area of stationary Markov processes both from a probabilistic and a dynamical point of view." --MONATSHEFTE FÜR MATHEMATIK

Transferability of Fracture Mechanical Characteristics

Transferability of Fracture Mechanical Characteristics PDF Author: Ivo Dlouhý
Publisher: Springer Science & Business Media
ISBN: 9401006083
Category : Science
Languages : en
Pages : 380

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Book Description
Five laboratories from France, Hungary and the Czech Republic have solved a Project supported fmancially by NATO within the Science for Peace Program (under Nr. 972655) for three years. The project, titled Fracture ResistanceofSteelsfor Containers of Spent Nuclear Fuel, was focused (i) on the generation of data needed for the qualification procedure of a new container introduced by Skoda Nuclear Machinery and (ii) on a number of topics of scientific nature associated with the interesting field of transferability of fracture mechanical data-, It has been found during numerous conference presentations of project results that the knowledge developed within the project would be more attractive when published in a more comprehensive form. This was the reason why the final project workshop was arranged as a meeting of project collaborators and contributing invited experts working in very similar field. The main scope of the final project workshop, titled Transferability of Fracture Mechanical Data and held in Brno from 5 to 6 November 200I, was to bring together project collaborators with a number of invited international experts, both covering the spectrum of topics solved within the project and reviewing the project results in the presence ofthese specialists. A totalof34 colleagues from 7 European countries and the USA participated in the workshop.

Rapid Inexpensive Tests for Determining Fracture Toughness

Rapid Inexpensive Tests for Determining Fracture Toughness PDF Author: National Research Council (U.S.). Committee on Rapid Inexpensive Tests for Determining Fracture Toughness
Publisher: National Academies
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 266

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Time-Dependent Fracture Mechanics

Time-Dependent Fracture Mechanics PDF Author: Dominique P. Miannay
Publisher: Springer Science & Business Media
ISBN: 1461301556
Category : Technology & Engineering
Languages : en
Pages : 480

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Book Description
Intended for engineers, researchers, and graduate students dealing with materials science, structural design, and nondestructive testing and evaluation, this book represents a continuation of the author's "Fracture Mechanics" (1997). It will appeal to a variety of audiences: The discussion of design codes and procedures will be of use to practicing engineers, particularly in the nuclear, aerospace, and pipeline industries; the extensive bibliography and discussion of recent results will make it a useful reference for academic researchers; and graduate students will find the clear explanations and worked examples useful for learning the field. The book begins with a general treatment of fracture mechanics in terms of material properties and loading and provides up-to-date reviews of the ductile-brittle transition in steels and of methods for analyzing the risk of fracture. It then discusses the dynamics of fracture and creep in homogeneous and isotropic media, including discussions of high-loading-rate characteristics, the behavior of stationary cracks in elastic media under stress, and the propagation of cracks in elastic media. This is followed by an analysis of creep and crack initiation and propagation, describing, for example, the morphology and incubation times of crack initiation and growth and the effects of high temperatures. The book concludes with treatments of cycling deformation and fatigue, creep-fatigue fractures, and crack initiation and propagation. Problems at the end of each chapter serve to reinforce and test the student's knowledge and to extend some of the discussions in the text. Solutions to half of the problems are provided.

A Closer Look at Effects of the Loading Rate on Fracture Toughness in the Ductile-to-Brittle Transition Regime of a Ferritic Steel

A Closer Look at Effects of the Loading Rate on Fracture Toughness in the Ductile-to-Brittle Transition Regime of a Ferritic Steel PDF Author: Hans-Jakob Schindler
Publisher:
ISBN:
Category : Ferritic steel
Languages : en
Pages : 10

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Book Description
An increased loading rate causes not only a shift of the ductile-to-brittle transition curve, but also a slight change of the shape of this curve. The latter tends to become steeper as the loading rate increases. This effect was observed even at loading rates that are considered to be quasi-static according to ASTM E1921-13: Standard Test Method for Determination of Reference Temperature, T0, for Ferritic Steels in the Transition Range, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2013. Actually, the coefficient 0.019 in the exponent of the MC turned out to be substantially higher at elevated loading rates. This means that a basic assumption of the evaluation procedure of ASTM E1921 is not met, which leads to an increased uncertainty of T0 or T0,x, respectively. This effect of is most pronounced in testing at elevated loading rates using the single-temperature option. An improved method to determine the reference temperature is proposed, where the exponent in the median transition curve in ASTM E1921 is considered to be an open parameter. The resulting reference temperatures, denoted as T100 andT100,x, respectively, are expected to be more accurate than standard T0, which is confirmed by comparison with experimental data. Furthermore, the validity requirements for T100 are less restrictive and more suitable than those in ASTM E1921, since they do not depend on the outcome of the tests. Based on the improved data, an improved estimation formula for the rate-induced shift of T0 is derived. Suggestions are made for improvement of ASTM E1921.

Rapid Load Fracture Testing

Rapid Load Fracture Testing PDF Author: Ravinder Chona
Publisher: ASTM International
ISBN: 080311429X
Category : Metals
Languages : en
Pages : 187

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Book Description