The Use of Small Graphite Specimen Test Data for Large Core Components for HTGR

V-shape specimen testing is a relatively new, simple and useful technique to characterize the thermal-fatigue resistance of materials subjected to combined thermal/mechanical loadings, and to rank and select materials. However, the V-shape specimen test data, similar to many other life test data, always contain an inherent scatter not only because of material non-uniformity but also of the difficulties in operating control, such as loading, boundary conditions, and environment. Therefore, statistical and probabilistic approaches have to be used to interpret the test data in order to implement the observations into new product designs. In this paper, the V-shape specimen test data are selected, analyzed and the scatter properties of the test data are fitted using several continuous probability distribution functions. The results are compared, and the root failure mechanisms of the V-specimens are also discussed. Finally, the main observations are summarized, and a recommendation is provided.

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The determination of curves from single-specimen test data

International Journal of Pressure Vessels and Piping ◽

10.1016/0308-0161(85)90005-5 ◽

1985 ◽

Vol 21 (4) ◽

pp. 261-284 ◽

Cited By ~ 2

Author(s):

Zhongxin Guan ◽

Liang Liu ◽

Nansheng Yang

Keyword(s):

Test Data ◽

Single Specimen ◽

Specimen Test

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The Background to Light Water Reactor Environment Fatigue Evaluation Methods for Austenitic Stainless Steel and Their Application to Sample Pressurised Water Reactor Components

ASME 2011 Pressure Vessels and Piping Conference: Volume 3 ◽

10.1115/pvp2011-57389 ◽

2011 ◽

Author(s):

C. T. Watson

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Test Data ◽

Cylindrical Specimen ◽

Fatigue Curve ◽

Light Water Reactor ◽

Light Water ◽

Water Reactor ◽

Specimen Test ◽

Asme Code

There is now a large amount of small cylindrical specimen test data, which indicates that in a Light Water Reactor (LWR) environment, compared to that in air, the fatigue life of stainless steel is significantly reduced. The current ASME III design fatigue curve does not explicitly include factors to account for a LWR environment. Using the available cylindrical specimen test data, methods for accounting for a LWR environment in fatigue assessments have been proposed in NuReg/CR-6909 and in two American Society of Mechanical Engineers (ASME) code cases. One of the code cases (N-792) uses a penalty factor (Fen) approach, similar to that in NuReg/CR-6909, another (N-761) utilizes a set of environmentally corrected fatigue curves. A third code case, which is still under development, uses a flaw tolerance approach. In this paper the background to the methods for correcting for a LWR environment in fatigue calculations is presented. The safety margin present in the ASME fatigue design methodology is discussed and a short review of civil nuclear plant operating and geometrical features testing experience provided. The NuReg/CR-6909 and ASME code case N-761 methods are applied to a number of ASME III Class 1 austenitic stainless steel components, and the cumulative usage factors calculated compared with those obtained using the ASME 2007 design fatigue curve. An objective of the paper is to highlight some of the issues arising out of applying the newly proposed methods to reactor plant components.

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Establishing a methodology to predict the crack initiation load in through-wall cracked components using tensile specimen test data

International Journal of Pressure Vessels and Piping ◽

10.1016/j.ijpvp.2010.08.014 ◽

2010 ◽

Vol 87 (12) ◽

pp. 737-745 ◽

Cited By ~ 6

Author(s):

Sanjeev Saxena ◽

N. Ramakrishnan ◽

J.S. Chouhan

Keyword(s):

Crack Initiation ◽

Test Data ◽

Tensile Specimen ◽

Specimen Test

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Test Validation Without Measurement

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000253 ◽

2016 ◽

Vol 32 (3) ◽

pp. 204-214 ◽

Cited By ~ 2

Author(s):

Emilie Lacot ◽

Mohammad H. Afzali ◽

Stéphane Vautier

Keyword(s):

Test Data ◽

Test Scores ◽

Scientific Explanation ◽

Test Validation ◽

Clinical Tests ◽

Ethical Perspective ◽

Power Of Test ◽

Memory Accuracy ◽

Social Uses ◽

Special Case

Abstract. Test validation based on usual statistical analyses is paradoxical, as, from a falsificationist perspective, they do not test that test data are ordinal measurements, and, from the ethical perspective, they do not justify the use of test scores. This paper (i) proposes some basic definitions, where measurement is a special case of scientific explanation; starting from the examples of memory accuracy and suicidality as scored by two widely used clinical tests/questionnaires. Moreover, it shows (ii) how to elicit the logic of the observable test events underlying the test scores, and (iii) how the measurability of the target theoretical quantities – memory accuracy and suicidality – can and should be tested at the respondent scale as opposed to the scale of aggregates of respondents. (iv) Criterion-related validity is revisited to stress that invoking the explanative power of test data should draw attention on counterexamples instead of statistical summarization. (v) Finally, it is argued that the justification of the use of test scores in specific settings should be part of the test validation task, because, as tests specialists, psychologists are responsible for proposing their tests for social uses.

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