Standard Test Method for Measurement of Fracture Toughness

SIGNIFICANCE AND USE
Assuming the presence of a preexisting, sharp, fatigue crack, the material fracture toughness values identified by this test method characterize its resistance to: (1) fracture of a stationary crack, (2) fracture after some stable tearing, (3) stable tearing onset, and (4) sustained stable tearing. This test method is particularly useful when the material response cannot be anticipated before the test. Application of procedures in Test Method E1921 is recommended for testing ferritic steels that undergo cleavage fracture in the ductile-to-brittle transition.
These fracture toughness values may serve as a basis for material comparison, selection, and quality assurance. Fracture toughness can be used to rank materials within a similar yield strength range.  
These fracture toughness values may serve as a basis for structural flaw tolerance assessment. Awareness of differences that may exist between laboratory test and field conditions is required to make proper flaw tolerance assessment.
The following cautionary statements are based on some observations.
Particular care must be exercised in applying to structural flaw tolerance assessment the fracture toughness value associated with fracture after some stable tearing has occurred. This response is characteristic of ferritic steel in the transition regime. This response is especially sensitive to material inhomogeneity and to constraint variations that may be induced by planar geometry, thickness differences, mode of loading, and structural details.
The J-R curve from bend-type specimens recommended by this test method (SE(B), C(T), and DC(T)) has been observed to be conservative with respect to results from tensile loading configurations.  
The values of δc, δu, Jc, and Ju   may be affected by specimen dimensions.
SCOPE
1.1 This test method covers procedures and guidelines for the determination of fracture toughness of metallic materials using the following parameters: K, J, and CTOD (δ). Toughness can be measured in the R-curve format or as a point value. The fracture toughness determined in accordance with this test method is for the opening mode (Mode I) of loading.
1.2 The recommended specimens are single-edge bend, [SE(B)], compact, [C(T)], and disk-shaped compact, [DC(T)]. All specimens contain notches that are sharpened with fatigue cracks.
1.2.1 Specimen dimensional (size) requirements vary according to the fracture toughness analysis applied. The guidelines are established through consideration of material toughness, material flow strength, and the individual qualification requirements of the toughness value per values sought.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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.
Note 1—Other standard methods for the determination of fracture toughness using the parameters K, J, and CTOD are contained in Test Methods E399, E813, E1152, E1290, and E1737. This test method was developed to provide a common method for determining all applicable toughness parameters from a single test.    
A14.1.1 This annex covers the determination of the rate dependent JIc(t) and the J-integral versus crack growth resistance curve (J-R(t) curve) for metallic materials under conditions where the loading rate exceeds that allowed for conventional (static) testing, see Section 8.4.2.  
A15.1.1 The normalization technique can be used in some cases to obtain a J-R curve directly from a force displacement record taken together with initial and final crack size measurements taken from the specimen fracture surface. Additional restrictions are applied (see A14.1.3) which limit the app...

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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
´1
Designation: E1820 – 09
Standard Test Method for
1
Measurement of Fracture Toughness
This standard is issued under the fixed designation E1820; 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—Sections A2.4.2, A2.4.2.2, and A3.5.2.2 were editorially corrected in July 2010.
1. Scope E8 Test Methods for Tension Testing of Metallic Materials
E21 Test Methods for Elevated Temperature Tension Tests
1.1 This test method covers procedures and guidelines for
of Metallic Materials
the determination of fracture toughness of metallic materials
E399 Test Method for Linear-Elastic Plane-Strain Fracture
using the following parameters: K, J, and CTOD (d). Tough-
Toughness K of Metallic Materials
Ic
nesscanbemeasuredintheR-curveformatorasapointvalue.
E813 TestMethodforJIc,AMeasureofFractureToughness
The fracture toughness determined in accordance with this test
E1152 Test Method for Determining-J-R-Curves
method is for the opening mode (Mode I) of loading.
E1290 Test Method for Crack-Tip Opening Displacement
1.2 The recommended specimens are single-edge bend,
(CTOD) Fracture Toughness Measurement
[SE(B)], compact, [C(T)], and disk-shaped compact, [DC(T)].
E1737 Test Method for J-Integral Characterization of Frac-
All specimens contain notches that are sharpened with fatigue
3
ture Toughness (Discontinued 1998)
cracks.
E1823 Terminology Relating to Fatigue and Fracture Test-
1.2.1 Specimen dimensional (size) requirements vary ac-
ing
cording to the fracture toughness analysis applied. The guide-
E1921 Test Method for Determination of Reference Tem-
lines are established through consideration of material tough-
perature, T , for Ferritic Steels in the Transition Range
o
ness, material flow strength, and the individual qualification
E1942 Guide for Evaluating Data Acquisition Systems
requirements of the toughness value per values sought.
Used in Cyclic Fatigue and Fracture Mechanics Testing
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
3. Terminology
only.
3.1 Terminology E1823 is applicable to this test method.
1.4 This standard does not purport to address all of the
3.2 Definitions:
safety concerns, if any, associated with its use. It is the
−1
3.2.1 compliance [LF ], n—the ratio of displacement in-
responsibility of the user of this standard to establish appro-
crement to force increment.
priate safety and health practices and determine the applica-
3.2.2 crack displacement [L], n—the separation vector be-
bility of regulatory limitations prior to use.
tween two points (on the surfaces of a deformed crack) that
NOTE 1—Other standard methods for the determination of fracture
were coincident on the surfaces of an ideal crack in the
toughness using the parameters K, J, and CTOD are contained in Test
undeformed condition.
Methods E399, E813, E1152, E1290, and E1737. This test method was
3.2.2.1 Discussion—In this practice, displacement, v, is the
developed to provide a common method for determining all applicable
total displacement measured by clip gages or other devices
toughness parameters from a single test.
spanning the crack faces.
2. Referenced Documents
3.2.3 crack extension, Da [L], n—an increase in crack size.
−1 −2
2
3.2.4 crack-extension force, G [FL or FLL ], n—the
2.1 ASTM Standards:
elastic energy per unit of new separation area that is made
E4 Practices for Force Verification of Testing Machines
availableatthefrontofanidealcrackinanelasticsolidduring
a virtual increment of forward crack extension.
1
3.2.5 crack size, a [L], n—a lineal measure of a principal
This test method is under the jurisdiction ofASTM Committee E08 on Fatigue
and Fracture and is the direct responsibility of Subcommittee E08.07 on Fracture
planar dimension of a crack. This measure is commonly used
Mechanics.
in the calculation of quantities descriptive of the stress and
Current edition approved Nov. 1, 2009. Published December 2009. Originally
displacement fields, and is often also termed crack size or
approved in 1996. Last previous edition approved in 2008 as E1820–08a.DOI:
10.1520/E1820-09. depth.
2
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
3
Standards volume information, refer to the standard’s Document Summary page on Withdrawn. The last approved version of this historical standard is referenced
the ASTM website. on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
...

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:E1820–09 Designation: E1820 – 09
Standard Test Method for
1
Measurement of Fracture Toughness
This standard is issued under the fixed designation E1820; 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—Sections A2.4.2, A2.4.2.2, and A3.5.2.2 were editorially corrected in July 2010.
1. Scope
1.1 This test method covers procedures and guidelines for the determination of fracture toughness of metallic materials using
the following parameters: K, J, and CTOD (d).Toughness can be measured in the R-curve format or as a point value.The fracture
toughness determined in accordance with this test method is for the opening mode (Mode I) of loading.
1.2 The recommended specimens are single-edge bend, [SE(B)], compact, [C(T)], and disk-shaped compact, [DC(T)]. All
specimens contain notches that are sharpened with fatigue cracks.
1.2.1 Specimen dimensional (size) requirements vary according to the fracture toughness analysis applied. The guidelines are
established through consideration of material toughness, material flow strength, and the individual qualification requirements of
the toughness value per values sought.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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.
NOTE 1—Other standard methods for the determination of fracture toughness using the parameters K, J, and CTOD are contained in Test Methods
E399,E813,E1152,E1290,andE1737.Thistestmethodwasdevelopedtoprovideacommonmethodfordeterminingallapplicabletoughnessparameters
from a single test.
2. Referenced Documents
2
2.1 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
E8 Test Methods for Tension Testing of Metallic Materials
E21 Test Methods for Elevated Temperature Tension Tests of Metallic Materials
E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K of Metallic Materials
Ic
E813 Test Method for JIc, A Measure of Fracture Toughness
E1152 Test Method for Determining-J-R-Curves
E1290 Test Method for Crack-Tip Opening Displacement (CTOD) Fracture Toughness Measurement
E1737 Test Method for J-Integral Characterization of Fracture Toughness (Discontinued 1998)
E1823 Terminology Relating to Fatigue and Fracture Testing
E1921 Test Method for Determination of Reference Temperature, T , for Ferritic Steels in the Transition Range
o
E1942 Guide for Evaluating Data Acquisition Systems Used in Cyclic Fatigue and Fracture Mechanics Testing
3. Terminology
3.1 Terminology E1823 is applicable to this test method.
3.2 Definitions:
−1
3.2.1 compliance [LF ], n—the ratio of displacement increment to force increment.
3.2.2 crack displacement [L], n—the separation vector between two points (on the surfaces of a deformed crack) that were
coincident on the surfaces of an ideal crack in the undeformed condition.
1
This test method is under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture and is the direct responsibility of Subcommittee E08.07 on Fracture
Mechanics.
Current edition approved Nov. 1, 2009. Published December 2009. Originally approved in 1996. Last previous edition approved in 2008 as E1820–08a.DOI:
10.1520/E1820-09.
2
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandards
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.
1

---------------------- Page: 1 ----------------------
´1
E1820 – 09
3.2.2.1 Discussion—Inthispractice,displacement,v,isthetotaldisplacementmeasuredbyclipgagesorotherdevicesspanning
the crack faces.
3.2.3 crack extension, Da [L], n—an increase in crack size.
−1 −2
3.2.4 crack-extension force, G [FL or FLL ], n—the elastic energy per unit of new separation area that is made available
at the front of an ideal crack in an elastic solid during a virtual increment of forward crack extension.
3.2.5 crack size, a [L], n
...

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