ASTM E739-10(2015)

Standard Practice for Statistical Analysis of Linear or Linearized Stress-Life (<emph type="bdit">S-N</emph>) and Strain-Life (&#x3b5;-<emph type="bdit" >N</emph>) Fatigue Data

SIGNIFICANCE AND USE
4.1 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

• Status: Historical
• Publication Date: 30-Sep-2015
• ICS: 19.060 - Mechanical testing
• Technical Committee: E08 - Fatigue and Fracture
• Drafting Committee: E08.04 - Structural Applications

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 (Reapproved 2015)
Standard Practice 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. A number 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
3.1 The terms used in this practice shall be used as defined
1.1 This practice covers only S-N and ε-N relationships that
in Definitions E206 and E513. In addition, the following
may be reasonably approximated by a straight line (on appro-
terminology is used:
priate coordinates) for a specific interval of stress or strain. It
3.1.1 dependent variable—the fatigue life N (or the loga-
presents elementary procedures that presently reflect good
rithm of the fatigue life).
practice in modeling and analysis. However, because the actual
3.1.1.1 Discussion—Log (N) is denoted Y in this practice.
S-N or ε-N relationship is approximated by a straight line only
3.1.2 independent variable—the selected and controlled
within a specific interval of stress or strain, and because the
variable (namely, stress or strain). It is denoted X in this
actual fatigue life distribution is unknown, it is not recom-
practice when plotted on appropriate coordinates.
mended that (a) the S-N or ε-N curve be extrapolated outside
3.1.3 log-normal distribution—the distribution of N when
the interval of testing, or (b) the fatigue life at a specific stress
log (N) is normally distributed. (Accordingly, it is convenient
or strain amplitude be estimated below approximately the fifth
to analyze log (N) using methods based on the normal
percentile (P . 0.05). As alternative fatigue models and
distribution.)
statistical analyses are continually being developed, later
3.1.4 replicate (repeat) tests—nominally identical tests on
revisions of this practice may subsequently present analyses
different randomly selected test specimens conducted at the
that permit more complete interpretation of S-N and ε-N data.
same nominal value of the independent variable X. Such
replicate or repeat tests should be conducted independently; for
2. Referenced Documents
example, each replicate test should involve a separate set of the
2
test machine and its settings.
2.1 ASTM Standards:
3.1.5 run out—no failure at a specified number of load
E206 Definitions of Terms Relating to Fatigue Testing and
cycles (Practice E468).
the Statistical Analysis of Fatigue Data; Replaced by
3
3.1.5.1 Discussion—The analyses illustrated in this practice
E 1150 (Withdrawn 1988)
do not apply when the data include either run-outs (or
E468 Practice for Presentation of Constant Amplitude Fa-
suspended tests). Moreover, the straight-line approximation of
tigue Test Results for Metallic Materials
the S-N or ε-N relationship may not be appropriate at long lives
E513 Definitions of Terms Relating to Constant-Amplitude,
when run-outs are likely.
Low-Cycle Fatigue Testing; Replaced by E 1150 (With-
3 3.1.5.2 Discussion—For purposes of statistical analysis, a
drawn 1988)
run-out may be viewed as a test specimen that has either been
E606/E606M Test Method for Strain-Controlled Fatigue
removed from the test or is still running at the time of the data
Testing
analysis.
4. Significance and Use
1
This practice is under the jurisdiction of ASTM Committee E08 on Fatigue and
4.1 Materials scientists and engineers are making increased
Fracture and is the direct responsibility of Subcommittee E08.04 on Structural
Applications. use of statistical analyses in interpreting S-N and ε-N fatigue
Current edition approved Oct. 1, 2015. Published November 2015. Originally
data. Statistical analysis applies when the given data can be
approved in 1980. Last previous edition approved in 2010 as E739 – 10. DOI:
reasonably assumed to be a random sample of (or representa-
10.1520/E0739-10R15.
2
tion of) some specific defined population or universe of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
material of interest (under specific test conditions), and it is
Standards volume information, refer to the standard’s Document Summary page on
desired either to characterize the material or to predict the
the ASTM website.
3 performance of future random samples of the material (under
The last approved version of this historical standard is referenced on www.ast-
m.org. similar test conditions), or both.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
Designation: E739 − 10 E739 − 10 (Reapproved 2015)
Standard Practice 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. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. 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.
2. Referenced Documents
2
2.1 ASTM Standards:
E206 Definitions of Terms Relating to Fatigue Testing and the Statistical Analysis of Fatigue Data; Replaced by E 1150
3
(Withdrawn 1988)
E468 Practice for Presentation of Constant Amplitude Fatigue Test Results for Metallic Materials
E513 Definitions of Terms Relating to Constant-Amplitude, Low-Cycle Fatigue Testing; Replaced by E 1150 (Withdrawn
3
1988)
E606E606/E606M Test Method for Strain-Controlled Fatigue Testing
3. Terminology
3.1 The terms used in this practice shall be used as defined in Definitions E206 and E513. In addition, the following terminology
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
tests). Moreover, the straight-line approximation of the S-N or ε-N relationship may not be appropriate at long lives when run-outs
are likely.
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 Nov. 1, 2010Oct. 1, 2015. Published November 2010November 2015. Originally approved in 1980. Last previous edition approved in 20042010
ε1
as E739 – 91 (2004)E739 – 10. . DOI: 10.1520/E0739-10.10.1520/E0739-10R15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
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

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E739 − 10 (2015)
3.1.5.2 Discussion—For purposes of statistical analysis, a 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.
4. Significance and Use
4.1 Materials scientists and engineers are making increased use of statistical analyses in interpreting S-N and ε-N fatigue data.
S
...