ASTM E1681-03(2008)

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.
Designation:E1681–03 Designation: E 1681 – 03 (Reapproved 2008)
Standard Test Method for
Determining Threshold Stress Intensity Factor for
Environment-Assisted Cracking of Metallic Materials
This standard is issued under the fixed designation E1681; 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
1.1 Thistestmethodcoversthedeterminationoftheenvironment-assistedcrackingthresholdstressintensityfactorparameters,
K andK ,formetallicmaterialsfromconstant-forcetestingoffatigueprecrackedbeamorcompactfracturespecimensand
IEAC EAC
from constant-displacement testing of fatigue precracked bolt-load compact fracture specimens.
1.2 This test method is applicable to environment-assisted cracking in aqueous or other aggressive environments.
1.3 Materials that can be tested by this test method are not limited by thickness or by strength as long as specimens are of
sufficient thickness and planar size to meet the size requirements of this test method.
1.4 Arange of specimen sizes with proportional planar dimensions is provided, but size may be variable and adjusted for yield
strength and applied force. Specimen thickness is a variable independent of planar size.
1.5 Specimen configurations other than those contained in this test method may be used, provided that well-established stress
intensity calibrations are available and that specimen dimensions are of sufficient size to meet the size requirements of this test
method during testing.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D1141 Specification for Substitute Ocean Water Practice for the Preparation of Substitute Ocean Water
E8/E8M Test Methods for Tension Testing of Metallic Materials
E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K of Metallic Materials
Ic
E647 Test Method for Measurement of Fatigue Crack Growth Rates
E1823 Terminology Relating to Fatigue and Fracture Testing
G1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
G5 Standard Reference Test Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements
G15 Terminology Relating to Corrosion and Corrosion Testing
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms relating to fracture testing used in this test method, refer to Terminology E1823.
3.1.2 For definitions of terms relating to corrosion testing used in this test method, refer to Terminology G15.
3.1.3 stress-corrosion cracking (SCC)—a cracking process that requires the simultaneous action of a corrodent and sustained
tensile stress.
–3/2
3.1.4 stress intensity factor threshold for plane strain environment-assisted cracking (K [FL ])—the highest value of the
IEAC
stressintensityfactor(K)atwhichcrackgrowthisnotobservedforaspecifiedcombinationofmaterialandenvironmentandwhere
the specimen size is sufficient to meet requirements for plane strain as described in Test Method E399.
–3/2
3.1.5 stress intensity factor threshold for environment-assisted cracking (K [FL ])—the highest value of the stress
EAC
intensity factor (K) at which crack growth is not observed for a specified combination of material and environment and where the
measured value may depend on specimen thickness.
This test method is under the jurisdiction ofASTM Committee E08 on Fatigue and Fracture and is the direct responsibility of Subcommittee E08.06 on Crack Growth
Behavior.
´1
Current edition approved Sept. 10, 2003. Published November 2003. Originally approved in 1995. Last previous edition approved in 1999 as E1681-99 .
Current edition approved Nov. 1, 2008. Published February 2009. Originally approved in 1995. Last previous edition approved in 2003 as E1681-03.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandards
, Vol 11.02.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 1681 – 03 (2008)
3.1.6 physical crack size (a [L])—the distance from a reference plane to the observed crack front.This distance may represent
p
an average of several measurements along the crack front. The reference plane depends on the specimen form, and it is normally
taken to be either the boundary or a plane containing either the loadline or the centerline of a specimen or plate. The reference
plane is defined prior to specimen deformation.
3.1.7 original crack size (a [L])—the physical crack size at the start of testing.
o
3.1.8 original uncracked ligament (b [L])—distance from the original crack front to the back edge of the specimen (b =W–
o o
a ).
o
3.1.9 specimen thickness (B[L])—the side-to-side dimension of the specimen being tested.
–2
3.1.10 tensile strength (s [FL ])—the maximum tensile stress that a material is capable of sustaining. Tensile strength is
TS
calculated from the maximum force during a tension test carried to rupture and the original cross-section area of the specimen.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 environment-assisted cracking (EAC)—a cracking process in which the environment promotes crack growth or higher
crack growth rates than would occur without the presence of the environment.
3.2.2 normalized crack size (a/W)—the ratio of crack size, a, to specimen width, W. Specimen width is measured from a
reference position such as the front edge in a bend specimen or the loadline in the compact specimen to the back edge of the
specimen.
–2
3.2.3 yield strength (s [FL ])—the stress at which a material exhibits a specific limiting deviation from the proportionality
YS
of stress to strain. This deviation is expressed in terms of strain.
NOTE 1—In this test method, the yield strength determined by the 0.2% offset method is used.
–2
3.2.4 effective yield strength (s [FL ])—an assumed value of uniaxial yield strength that represents the influences of plastic
Y
yielding upon fracture test parameters. For use in this method, it is calculated as the average of the 0.2% offset yield strength s
YS, and the ultimate tensile strength, s ,or
TS
s 5 ~s 1s !/2 (1)
Y YS TS
3.2.5 notchlength(a (L))—thedistancefromareferenceplanetothefrontofthemachinednotch.Thereferenceplanedepends
n
on the specimen form and normally is taken to be either the boundary or a plane containing either the loadline or the centerline
of a specimen or plate. The reference plane is defined prior to specimen deformation.
4. Summary of Test Method
4.1 This test method involves testing of single-edge notched [SE(B)] specimens, compact [C(T)] specimens, or bolt-load
compact [MC(W)] specimens, precracked in fatigue. The single-edge notched beam specimen is tested by dead weight loading.
Anenvironmentalchamberiseitherattachedtothespecimen,orthespecimeniscontainedwithinthechamber.Thechambermust
enclose the portion of the specimen where the crack tip is located. Prescribed environmental conditions must be established and
maintained within the chamber at all times during the test.
4.1.1 Specimens shall be deadweight loaded or otherwise held under constant force or held under constant displacement
(defined in 6.2) for a prescribed length of time, during which failure by crack growth leading to fracture may or may not occur.
K and K are defined as the highest value of stress intensity factor at which neither failure nor crack growth occurs. The
IEAC EAC
stress intensity factor (K) is calculated from an expression based on linear elastic stress analysis. To establish a suitable crack-tip
conditionforconstantforcetests,thestress-intensitylevelatwhichthefatigueprecrackingofthespecimenisconductedislimited
to a value substantially less than the measured K or K values. For constant displacement tests, the stress-intensity level at
IEAC EAC
which the fatigue precracking of the specimen is conducted is limited to the requirements of Test Method E399. The validity of
the K value determined by this test method depends on meeting the size requirements to ensure plane strain conditions, as
IEAC
stated inTest Method E399.The validity of the K value depends on meeting the size requirements for linear elastic behavior,
EAC
as stated in the Test Method E647.
4.1.2 This test method can produce information on the onset of environment-assisted crack growth. Crack growth rate
information can be obtained after crack nucleation, but the method for obtaining this information is not part of this test method
(1).
4.2 The mechanisms of environment-assisted cracking are varied and complex. Measurement of a K or K value for a
EAC IEAC
given combination of material and environmental provides no insight into the particular cracking mechanism that was either
operative or dominant. Two prominent theories of environment-assisted cracking are anodic reaction and hydrogen embrittlement
(2). The data obtained from this test method may be interpreted by either theory of environment-assisted cracking.
4.3 Specimen thickness governs the proportions of plane strain and plane stress deformation local to the crack tip, along with
the environmental contribution to cracking. Since these chemical and mechanical influences cannot be separated in some
material/environmentcombinations,thicknessmustbetreatedasavariable.Inthistestmethod,however,thestressinthespecimen
must remain elastic. For these reasons, two threshold values of EAC are defined by this test method. The measurement of K
IEAC
Annual Book of ASTM Standards, Vol 03.01.
The boldface numbers in parentheses refer to the list of references at the end of this standard.
E 1681 – 03 (2008)
requires that the thickness requirements of plane strain constraint are met.The less restrictive requirements of K are intended
EAC
for those conditions in which the results are a strong function of the thickness of the specimen and the application requires the
testing of specimens with thickness representative of the application.
4.4 Avariety of environmental (temperature, environment composition, and electrode potential, for example) and metallurgical
(yield strength, alloy composition, and specimen orientation) variables affect K and K .
EAC IEAC
5. Significance and Use
5.1 TheparametersK orK determinedbythistestmethodcharacterizetheresistancetocrackgrowthofamaterialwith
EAC IEAC
a sharp crack in specific environments under loading conditions in which the crack-tip plastic region is small compared with the
crack depth and the uncracked ligament. The less restrictive thickness requirements of K are intended for those conditions in
EAC
which the results are a strong function of the thickness of the specimen and the application requires the testing of specimens with
thickness representative of the application. Since the chemical and mechanical influences cannot be separated, in some
material/environment combinations, the thickness must be treated as a variable.AK or K value is believed to represent a
EAC IEAC
characteristicmeasurementofenvironment-assistedcrackingresistanceinaprecrackedspecimenexposedtoanenvironmentunder
sustained tensile loading.AK or K value may be used to estimate the relationship between failure stress and defect size
EAC IEAC
for a material under any service condition, where the combination of crack-like defects, sustained tensile loading and the same
specific environment would be expected to occur. (Background information concerning the development of this test method can
be found in Refs (3-18).
5.1.1 The apparent K or K of a material under a given set of chemical and electrochemical environmental conditions
EAC IEAC
is a function of the test duration. It is difficult to furnish a rigorous and scientific proof for the existence of a threshold (4, 5).
Therefore, application of K or K data in the design of service components should be made with awareness of the
EAC IEAC
uncertainty inherent in the concept of a true threshold for environment-assisted cracking in metallic materials (6, 18).Ameasured
K or K value for a particular combination of material and environment may, in fact, represent an acceptably low rate of
EAC IEAC
crack growth rather than an absolute upper limit for crack stability. Care should be exercised when service times are substantially
longer than test times.
5.1.2 The degree to which force deviations from static tensile stress will influence the apparent K or K of a material is
EAC IEAC
largely unknown. Small-amplitude cyclic loading, well below that needed to produce fatigue crack growth, superimposed on
sustained tensile loading was observed to significantly lower the apparent threshold for stress corrosion cracking in certain
instances (7, 8).Therefore,cautionshouldbeusedinapplyingK orK datatoservicesituationsinvolvingcyclicloading.
EAC IEAC
In addition, since this standard is for static loading, small-amplitude cyclic loading should be avoided during testing.
5.1.3 Insomematerial/environmentcombinations,thesmallerthespecimen,thelowerthemeasuredK value,whileinother
EAC
material/environment combinations the measured K value will be the lowest value (5, 9, 10, 11, 12). If, for the
IEAC
material/environment combination of interest, it is not known which specimen size will result in the lower measured value, then
it is suggested that the use of both specimen sizes should be considered; that is, specimens with thicknesses representative of the
application and specimens in which the thickness meets the requirements (see 7.2.1) of a K value.
IEAC
5.1.3.1 The user may optionally determine and report a K value or a K value.The specimen size validity requirements
EAC IEAC
foraK value meet the size requirements developed for Test Method E647 to achieve predominately elastic behavior in the
EAC
specimen. Test Method E647 size requirements for compact specimens should be applied to both the compact specimen and the
beam specimen. The specimen size validity requirements for a K value meet the size requirem
...

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:E1681–99 Designation: E 1681 – 03 (Reapproved 2008)
Standard Test Method for
Determining Threshold Stress Intensity Factor for
Environment-Assisted Cracking of Metallic Materials
This standard is issued under the fixed designation E1681; 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.
´ NOTE—Committee and Subcommittee jurisdictions were editorially revised in April 2000.
1. Scope
1.1 Thistestmethodcoversthedeterminationoftheenvironment-assistedcrackingthresholdstressintensityfactorparameters,
K andK ,formetallicmaterialsfromconstant-forcetestingoffatigueprecrackedbeamorcompactfracturespecimensand
IEAC EAC
from constant-displacement testing of fatigue precracked bolt-load compact fracture specimens.
1.2 This test method is applicable to environment-assisted cracking in aqueous or other aggressive environments.
1.3 Materials that can be tested by this test method are not limited by thickness or by strength as long as specimens are of
sufficient thickness and planar size to meet the size requirements of this test method.
1.4 Arange of specimen sizes with proportional planar dimensions is provided, but size may be variable and adjusted for yield
strength and applied force. Specimen thickness is a variable independent of planar size.
1.5 Specimen configurations other than those contained in this test method may be used, provided that well-established stress
intensity calibrations are available and that specimen dimensions are of sufficient size to meet the size requirements of this test
method during testing.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D1141 Specification for Substitute Ocean Water Practice for the Preparation of Substitute Ocean Water
E8/E8M Test Methods for Tension Testing of Metallic Materials
E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K of Metallic Materials
Ic
E647 Test Method for Measurement of Fatigue Crack Growth Rates
E1823 Terminology Relating to Fatigue and Fracture Testing
G1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
G5 Standard Reference Test Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements
G15 Terminology Relating to Corrosion and Corrosion Testing
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms relating to fracture testing used in this test method, refer to Terminology E1823.
3.1.2 For definitions of terms relating to corrosion testing used in this test method, refer to Terminology G15.
3.1.3 stress-corrosion cracking (SCC)—a cracking process that requires the simultaneous action of a corrodent and sustained
tensile stress.
–3/2
3.1.4 stress intensity factor threshold for plane strain environment-assisted cracking (K [FL ])—the highest value of the
IEAC
stressintensityfactor(K)atwhichcrackgrowthisnotobservedforaspecifiedcombinationofmaterialandenvironmentandwhere
the specimen size is sufficient to meet requirements for plane strain as described in Test Method E399.
–3/2
3.1.5 stress intensity factor threshold for environment-assisted cracking (K [FL ])—the highest value of the stress
EAC
ThistestmethodisunderthejurisdictionofASTMCommitteeE-8E08onFatigueandFractureandisthedirectresponsibilityofSubcommitteeE08.06onCrackGrowth
Behavior.
Current edition approvedApril 10, 1999.Nov. 1, 2008. PublishedAugust 1999.February 2009. Originally published as E1681-95.approved in 1995. Last previous edition
E1681-95.approved in 2003 as E1681-03.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandards
, Vol 11.02.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 1681 – 03 (2008)
intensity factor (K) at which crack growth is not observed for a specified combination of material and environment and where the
measured value may depend on specimen thickness.
3.1.6 physical crack size (a [L])—the distance from a reference plane to the observed crack front.This distance may represent
p
an average of several measurements along the crack front. The reference plane depends on the specimen form, and it is normally
taken to be either the boundary or a plane containing either the loadline or the centerline of a specimen or plate. The reference
plane is defined prior to specimen deformation.
3.1.7 original crack size (a [L])—the physical crack size at the start of testing.
o
3.1.8 original uncracked ligament (b [L])—distance from the original crack front to the back edge of the specimen (b =W–
o o
a ).
o
3.1.9 specimen thickness (B[L])—the side-to-side dimension of the specimen being tested.
–2
3.1.10 tensile strength (s [FL ])—the maximum tensile stress that a material is capable of sustaining. Tensile strength is
TS
calculated from the maximum force during a tension test carried to rupture and the original cross-section area of the specimen.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 environment-assisted cracking (EAC)—a cracking process in which the environment promotes crack growth or higher
crack growth rates than would occur without the presence of the environment.
3.2.2 normalized crack size (a/W)—the ratio of crack size, a, to specimen width, W. Specimen width is measured from a
reference position such as the front edge in a bend specimen or the loadline in the compact specimen to the back edge of the
specimen.
–2
3.2.3 yield strength (s [FL ])—the stress at which a material exhibits a specific limiting deviation from the proportionality
YS
of stress to strain. This deviation is expressed in terms of strain.
NOTE 1—In this test method, the yield strength determined by the 0.2% offset method is used.
–2
3.2.4 effective yield strength (s [FL ])—an assumed value of uniaxial yield strength that represents the influences of plastic
Y
yielding upon fracture test parameters. For use in this method, it is calculated as the average of the 0.2% offset yield strength s
YS, and the ultimate tensile strength, s ,or
TS
s 5 s 1s /2 (1)
~ !
Y YS TS
3.2.5 notchlength(a (L))—thedistancefromareferenceplanetothefrontofthemachinednotch.Thereferenceplanedepends
n
on the specimen form and normally is taken to be either the boundary or a plane containing either the loadline or the centerline
of a specimen or plate. The reference plane is defined prior to specimen deformation.
4. Summary of Test Method
4.1 This test method involves testing of single-edge notched [SE(B)] specimens, compact [C(T)] specimens, or bolt-load
compact [MC(W)] specimens, precracked in fatigue. The single-edge notched beam specimen is tested by dead weight loading.
Anenvironmentalchamberiseitherattachedtothespecimen,orthespecimeniscontainedwithinthechamber.Thechambermust
enclose the portion of the specimen where the crack tip is located. Prescribed environmental conditions must be established and
maintained within the chamber at all times during the test.
4.1.1 Specimens shall be deadweight loaded or otherwise held under constant force or held under constant displacement
(defined in 6.2) for a prescribed length of time, during which failure by crack growth leading to fracture may or may not occur.
K and K are defined as the highest value of stress intensity factor at which neither failure nor crack growth occurs. The
IEAC EAC
stress intensity factor (K) is calculated from an expression based on linear elastic stress analysis. To establish a suitable crack-tip
conditionforconstantforcetests,thestress-intensitylevelatwhichthefatigueprecrackingofthespecimenisconductedislimited
to a value substantially less than the measured K or K values. For constant displacement tests, the stress-intensity level at
IEAC EAC
which the fatigue precracking of the specimen is conducted is limited to the requirements of Test Method E399. The validity of
the K value determined by this test method depends on meeting the size requirements to ensure plane strain conditions, as
IEAC
stated inTest Method E399.The validity of the K value depends on meeting the size requirements for linear elastic behavior,
EAC
as stated in the Test Method E647.
4.1.2 This test method can produce information on the onset of environment-assisted crack growth. Crack growth rate
information can be obtained after crack nucleation, but the method for obtaining this information is not part of this test method
(1).
4.2 The mechanisms of environment-assisted cracking are varied and complex. Measurement of a K or K value for a
EAC IEAC
given combination of material and environmental provides no insight into the particular cracking mechanism that was either
operative or dominant. Two prominent theories of environment-assisted cracking are anodic reaction and hydrogen embrittlement
(2). The data obtained from this test method may be interpreted by either theory of environment-assisted cracking.
4.3 Specimen thickness governs the proportions of plane strain and plane stress deformation local to the crack tip, along with
the environmental contribution to cracking. Since these chemical and mechanical influences cannot be separated in some
Annual Book of ASTM Standards, Vol 03.01.
The boldface numbers in parentheses refer to the list of references at the end of this standard.
E 1681 – 03 (2008)
material/environmentcombinations,thicknessmustbetreatedasavariable.Inthistestmethod,however,thestressinthespecimen
must remain elastic. For these reasons, two threshold values of EAC are defined by this test method. The measurement of K
IEAC
requires that the thickness requirements of plane strain constraint are met.The less restrictive requirements of K are intended
EAC
for those conditions in which the results are a strong function of the thickness of the specimen and the application requires the
testing of specimens with thickness representative of the application.
4.4 Avariety of environmental (temperature, environment composition, and electrode potential, for example) and metallurgical
(yield strength, alloy composition, and specimen orientation) variables affect K and K .
EAC IEAC
5. Significance and Use
5.1 TheparametersK orK determinedbythistestmethodcharacterizetheresistancetocrackgrowthofamaterialwith
EAC IEAC
a sharp crack in specific environments under loading conditions in which the crack-tip plastic region is small compared with the
crack depth and the uncracked ligament. The less restrictive thickness requirements of K are intended for those conditions in
EAC
which the results are a strong function of the thickness of the specimen and the application requires the testing of specimens with
thickness representative of the application. Since the chemical and mechanical influences cannot be separated, in some
material/environment combinations, the thickness must be treated as a variable.AK or K value is believed to represent a
EAC IEAC
characteristicmeasurementofenvironment-assistedcrackingresistanceinaprecrackedspecimenexposedtoanenvironmentunder
sustained tensile loading.AK or K value may be used to estimate the relationship between failure stress and defect size
EAC IEAC
for a material under any service condition, where the combination of crack-like defects, sustained tensile loading and the same
specific environment would be expected to occur. (Background information concerning the development of this test method can
be found in Refs (3-18).
5.1.1 The apparent K or K of a material under a given set of chemical and electrochemical environmental conditions
EAC IEAC
is a function of the test duration. It is difficult to furnish a rigorous and scientific proof for the existence of a threshold (4, 5).
Therefore, application of K or K data in the design of service components should be made with awareness of the
EAC IEAC
uncertainty inherent in the concept of a true threshold for environment-assisted cracking in metallic materials (6, 18).Ameasured
K or K value for a particular combination of material and environment may, in fact, represent an acceptably low rate of
EAC IEAC
crack growth rather than an absolute upper limit for crack stability. Care should be exercised when service times are substantially
longer than test times.
5.1.2 The degree to which force deviations from static tensile stress will influence the apparent K or K of a material is
EAC IEAC
largely unknown. Small-amplitude cyclic loading, well below that needed to produce fatigue crack growth, superimposed on
sustained tensile loading was observed to significantly lower the apparent threshold for stress corrosion cracking in certain
instances (7, 8).Therefore,cautionshouldbeusedinapplyingK orK datatoservicesituationsinvolvingcyclicloading.
EAC IEAC
In addition, since this standard is for static loading, small-amplitude cyclic loading should be avoided during testing.
5.1.3 Insomematerial/environmentcombinations,thesmallerthespecimen,thelowerthemeasuredK value,whileinother
EAC
material/environment combinations the measured K value will be the lowest value (5, 9, 10, 11, 12). If, for the
IEAC
material/environment combination of interest, it is not known which specimen size will result in the lower measured value, then
it is suggested that the use of both specimen sizes should be considered; that is, specimens with thicknesses representative of the
application and specimens in which the thickness meets the requirements (see 7.2.1) of a K value.
IEAC
5.1.3.1 The user may optionally determine and report a K value or a K value.The specimen size validity requirements
EAC IEAC
foraK value meet the size requirements developed for Test Method E647 to achieve predominately elastic behavior in the
EAC
specimen. Test Method E647 size requirements for compact specimens should be applied to both the compact specimen and the
beam specimen. The specimen size validity requirements for a K value meet the size requirements developed for pl
...