ASTM E739-10
(Practice)Standard Practice for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (ε-N) Fatigue Data
Standard Practice for Statistical Analysis of Linear or Linearized Stress-Life (<bdit>S-N</bdit>) and Strain-Life (<bdit>ε-N</bdit>) Fatigue Data
SIGNIFICANCE AND USE
Materials scientists and engineers are making increased use of statistical analyses in interpreting S-N and ε-N fatigue data. Statistical analysis applies when the given data can be reasonably assumed to be a random sample of (or representation of) some specific defined population or universe of material of interest (under specific test conditions), and it is desired either to characterize the material or to predict the performance of future random samples of the material (under similar test conditions), or both.
SCOPE
1.1 This practice covers only S-N and ε-N relationships that may be reasonably approximated by a straight line (on appropriate coordinates) for a specific interval of stress or strain. It presents elementary procedures that presently reflect good practice in modeling and analysis. However, because the actual S-N or ε-N relationship is approximated by a straight line only within a specific interval of stress or strain, and because the actual fatigue life distribution is unknown, it is not recommended that (a) the S-N or ε-N curve be extrapolated outside the interval of testing, or (b) the fatigue life at a specific stress or strain amplitude be estimated below approximately the fifth percentile (P ≃ 0.05). As alternative fatigue models and statistical analyses are continually being developed, later revisions of this practice may subsequently present analyses that permit more complete interpretation of S-N and ε-N data.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E739 − 10
StandardPractice for
Statistical Analysis of Linear or Linearized Stress-Life (S-N)
1
and Strain-Life (ε-N) Fatigue Data
This standard is issued under the fixed designation E739; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This practice covers only S-N and ε-N relationships that 3.1 The terms used in this practice shall be used as defined
may be reasonably approximated by a straight line (on appro- in Definitions E206 and E513. In addition, the following
priate coordinates) for a specific interval of stress or strain. It terminology is used:
presents elementary procedures that presently reflect good 3.1.1 dependent variable—the fatigue life N (or the loga-
practiceinmodelingandanalysis.However,becausetheactual rithm of the fatigue life).
S-N or ε-N relationship is approximated by a straight line only 3.1.1.1 Discussion—Log (N) is denoted Y in this practice.
within a specific interval of stress or strain, and because the 3.1.2 independent variable—the selected and controlled
actual fatigue life distribution is unknown, it is not recom- variable (namely, stress or strain). It is denoted X in this
mended that (a) the S-N or ε-N curve be extrapolated outside practice when plotted on appropriate coordinates.
the interval of testing, or (b) the fatigue life at a specific stress 3.1.3 log-normal distribution—the distribution of N when
or strain amplitude be estimated below approximately the fifth log (N) is normally distributed. (Accordingly, it is convenient
percentile (P . 0.05). As alternative fatigue models and to analyze log (N) using methods based on the normal
statistical analyses are continually being developed, later distribution.)
revisions of this practice may subsequently present analyses 3.1.4 replicate (repeat) tests—nominally identical tests on
that permit more complete interpretation of S-N and ε-N data. different randomly selected test specimens conducted at the
same nominal value of the independent variable X. Such
2. Referenced Documents
replicateorrepeattestsshouldbeconductedindependently;for
2
example,eachreplicatetestshouldinvolveaseparatesetofthe
2.1 ASTM Standards:
test machine and its settings.
E206Definitions of Terms Relating to Fatigue Testing and
3.1.5 run out—no failure at a specified number of load
the Statistical Analysis of Fatigue Data; Replaced by
3
cycles (Practice E468).
E1150 (Withdrawn 1988)
3.1.5.1 Discussion—The analyses illustrated in this practice
E468Practice for Presentation of Constant Amplitude Fa-
do not apply when the data include either run-outs (or
tigue Test Results for Metallic Materials
suspended tests). Moreover, the straight-line approximation of
E513Definitions of Terms Relating to Constant-Amplitude,
the S-Nor ε-Nrelationshipmaynotbeappropriateatlonglives
Low-Cycle Fatigue Testing; Replaced by E1150 (With-
3
when run-outs are likely.
drawn 1988)
3.1.5.2 Discussion—For purposes of statistical analysis, a
E606Test Method for Strain-Controlled Fatigue Testing
run-out may be viewed as a test specimen that has either been
removed from the test or is still running at the time of the data
analysis.
1
ThispracticeisunderthejurisdictionofASTMCommitteeE08onFatigueand
Fracture and is the direct responsibility of Subcommittee E08.04 on Structural
4. Significance and Use
Applications.
Current edition approved Nov. 1, 2010. Published November 2010. Originally
4.1 Materials scientists and engineers are making increased
ε1
approved in 1980. Last previous edition approved in 2004 as E739–91(2004) .
use of statistical analyses in interpreting S-N and ε-N fatigue
DOI: 10.1520/E0739-10.
2
data. Statistical analysis applies when the given data can be
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
reasonably assumed to be a random sample of (or representa-
Standards volume information, refer to the standard’s Document Summary page on
tion of) some specific defined population or universe of
the ASTM website.
3 material of interest (under specific test conditions), and it is
The last approved version of this historical standard is referenced on
www.astm.org. desired either to characterize the material or to predict the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
E739 − 10
effective (equivalent) value of S or ε must be established for use in
performance of future random samples of the material (under
analysi
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation:E739–91 (Reapproved 2004) Designation: E739 – 10
Standard Practice for
Statistical Analysis of Linear or Linearized Stress-Life (S-N)
1
and Strain-Life (´-N) Fatigue Data
This standard is issued under the fixed designation E739; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1
´ NOTE—Editorial changes were made throughout in May 2006.
1. Scope
1.1 This practice covers only S-N and ´-N relationships that may be reasonably approximated by a straight line (on appropriate
coordinates) for a specific interval of stress or strain. It presents elementary procedures that presently reflect good practice in
modeling and analysis. However, because the actual S-N or ´-N relationship is approximated by a straight line only within a
specific interval of stress or strain, and because the actual fatigue life distribution is unknown, it is not recommended that (a) the
S-N or ´-N curve be extrapolated outside the interval of testing, or (b) the fatigue life at a specific stress or strain amplitude be
estimatedbelowapproximatelythefifthpercentile(P .0.05).Asalternativefatiguemodelsandstatisticalanalysesarecontinually
beingdeveloped,laterrevisionsofthispracticemaysubsequentlypresentanalysesthatpermitmorecompleteinterpretationof S-N
and ´-N data.
2. Referenced Documents
2
2.1 ASTM Standards:
E206 Discontinued 1988; Definitions of Terms Relating to Fatigue Testing and the Statistical Analysis of Fatigue Data;
Replaced by E1150
E467Practice for Verification of ConstantAmplitude Dynamic Forces in anAxial Fatigue Testing System Definitions of Terms
3
Relating to Fatigue Testing and the Statistical Analysis of Fatigue Data
E468 Practice for Presentation of Constant Amplitude Fatigue Test Results for Metallic Materials
3
E513 Definitions of Terms Relating to Constant-Amplitude, Low-Cycle Fatigue Testing3
E606 Practice for Strain-Controlled Fatigue Testing
3. Terminology
3.1 ThetermsusedinthispracticeshallbeusedasdefinedinDefinitionsE206andE513.Inaddition,thefollowingterminology
is used:
3.1.1 dependent variable—the fatigue life N (or the logarithm of the fatigue life).
3.1.1.1 Discussion—Log (N) is denoted Y in this practice.
3.1.2 independent variable—the selected and controlled variable (namely, stress or strain). It is denoted X in this practice when
plotted on appropriate coordinates.
3.1.3 log-normal distribution—the distribution of N when log ( N) is normally distributed. (Accordingly, it is convenient to
analyze log (N) using methods based on the normal distribution.)
3.1.4 replicate (repeat) tests—nominally identical tests on different randomly selected test specimens conducted at the same
nominal value of the independent variable X. Such replicate or repeat tests should be conducted independently; for example, each
replicate test should involve a separate set of the test machine and its settings.
3.1.5 run out—no failure at a specified number of load cycles (Practice E468).
3.1.5.1 Discussion—The analyses illustrated in this practice do not apply when the data include either run-outs (or suspended
1
This practice is under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture and is the direct responsibility of Subcommittee E08.04 on Structural
Applications.
Current edition approved May 1, 2004. Published June 2004. Originally approved in 1980. Last previous edition approved in 1998 as E739–91(1998). DOI:
10.1520/E0739-91R04E01.
´1
Current edition approved Nov. 1, 2010. Published November 2010. Originally approved in 1980. Last previous edition approved in 2004 as E739–91(2004) . DOI:
10.1520/E0739-10.
2
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The boldface numbers in parentheses refer to the list of references appended to this standard.
3
Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
E739 – 10
tests).Moreover,thestraight-lineapproximationofthe S-Nor ´-Nrelationshipmaynotbeappropriateatlongliveswhenrun-outs
are likely.
3.1.5.2
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.