ASTM D5045-14

Standard Test Methods for Plane-Strain Fracture Toughness and Strain Energy Release Rate of Plastic Materials

SIGNIFICANCE AND USE
5.1 The property KIc  (GIc) determined by these test methods characterizes the resistance of a material to fracture in a neutral environment in the presence of a sharp crack under severe tensile constraint, such that the state of stress near the crack front approaches plane strain, and the crack-tip plastic (or non-linear viscoelastic) region is small compared with the crack size and specimen dimensions in the constraint direction. A KIc value is believed to represent a lower limiting value of fracture toughness. This value has been used to estimate the relation between failure stress and defect size for a material in service wherein the conditions of high constraint described above would be expected. Background information concerning the basis for development of these test methods in terms of linear elastic fracture mechanics can be found in Refs  (1-5).3  
5.1.1 The KIc (GIc) value of a given material is a function of testing speed and temperature. Furthermore, cyclic loads have been found to cause crack extension at K values less than KIc (GIc). Crack extension under cyclic or sustained load will be increased by the presence of an aggressive environment. Therefore, application of KIc (GIc) in the design of service components should be made considering differences that may exist between laboratory tests and field conditions.  
5.1.2 Plane-strain fracture toughness testing is unusual in that sometimes there is no advance assurance that a valid KIc (GIc) will be determined in a particular test. Therefore it is essential that all of the criteria concerning validity of results be carefully considered as described herein.  
5.1.3 Clearly, it will not be possible to determine KIc (GIc) if any dimension of the available stock of a material is insufficient to provide a specimen of the required size.  
5.2 Inasmuch as the fracture toughness of plastics is often dependent on specimen process history, that is, injection molded, extruded, compression molded, etc., the spe...
SCOPE
1.1 These test methods are designed to characterize the toughness of plastics in terms of the critical-stress-intensity factor, KIc, and the energy per unit area of crack surface or critical strain energy release rate, GIc, at fracture initiation.  
1.2 Two testing geometries are covered by these test methods, single-edge-notch bending (SENB) and compact tension (CT).  
1.3 The scheme used assumes linear elastic behavior of the cracked specimen, so certain restrictions on linearity of the load-displacement diagram are imposed.  
1.4 A state-of-plane strain at the crack tip is required. Specimen thickness must be sufficient to ensure this stress state.  
1.5 The crack must be sufficiently sharp to ensure that a minimum value of toughness is obtained.  
1.6 The significance of these test methods and many conditions of testing are identical to those of Test Method E399, and, therefore, in most cases, appear here with many similarities to the metals standard. However, certain conditions and specifications not covered in Test Method E399, but important for plastics, are included.  
1.7 This protocol covers the determination of GIc as well, which is of particular importance for plastics.  
1.8 These test methods give general information concerning the requirements for KIc and GIc testing. As with Test Method E399, two annexes are provided which give the specific requirements for testing of the SENB and CT geometries.  
1.9 Test data obtained by these test methods are relevant and appropriate for use in engineering design.  
1.10 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: This standard and ISO 13586 address the same subject matter, but differ in technical content.

General Information

• Status: Historical
• Publication Date: 30-Nov-2014
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.10 - Mechanical Properties

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: D5045 − 14
Standard Test Methods for
Plane-Strain Fracture Toughness and Strain Energy Release
1
Rate of Plastic Materials
This standard is issued under the fixed designation D5045; 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* priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 These test methods are designed to characterize the
toughness of plastics in terms of the critical-stress-intensity
NOTE1—ThisstandardandISO13586addressthesamesubjectmatter,
factor, K , and the energy per unit area of crack surface or but differ in technical content.
Ic
critical strain energy release rate, G , at fracture initiation.
Ic
2. Referenced Documents
1.2 Two testing geometries are covered by these test
2
2.1 ASTM Standards:
methods, single-edge-notch bending (SENB) and compact
D638Test Method for Tensile Properties of Plastics
tension (CT).
D4000Classification System for Specifying Plastic Materi-
1.3 The scheme used assumes linear elastic behavior of the
als
cracked specimen, so certain restrictions on linearity of the
E399Test Method for Linear-Elastic Plane-Strain Fracture
load-displacement diagram are imposed.
Toughness K of Metallic Materials
Ic
1.4 A state-of-plane strain at the crack tip is required.
E691Practice for Conducting an Interlaboratory Study to
Specimen thickness must be sufficient to ensure this stress
Determine the Precision of a Test Method
state.
3. Terminology
1.5 The crack must be sufficiently sharp to ensure that a
minimum value of toughness is obtained.
3.1 Definitions:
3.1.1 compact tension, n—specimen geometry consisting of
1.6 The significance of these test methods and many con-
single-edge notched plate loaded in tension. See 3.1.5 for
ditions of testing are identical to those of Test Method E399,
reference to additional definition.
and, therefore, in most cases, appear here with many similari-
ties to the metals standard. However, certain conditions and
3.1.2 critical strain energy release rate, G ,n—toughness
Ic
specifications not covered in Test Method E399, but important
parameter based on energy required to fracture. See 3.1.5 for
for plastics, are included.
reference to additional definition.
1.7 This protocol covers the determination of G as well,
3.1.3 plane-strain fracture toughness, K ,n—toughness
Ic
Ic
which is of particular importance for plastics.
parameter indicative of the resistance of a material to fracture.
See 3.1.5 for reference to additional definition.
1.8 Thesetestmethodsgivegeneralinformationconcerning
the requirements for K and G testing.As with Test Method 3.1.4 single-edge notched bend, n—specimen geometry
Ic Ic
E399, two annexes are provided which give the specific
consisting of center-notched beam loaded in three-point bend-
requirements for testing of the SENB and CT geometries. ing. See 3.1.5 for reference to additional definition.
1.9 Testdataobtainedbythesetestmethodsarerelevantand
3.1.5 Reference is made toTest Method E399 for additional
appropriate for use in engineering design. explanation of definitions.
3.2 Definitions of Terms Specific to This Standard:
1.10 This standard does not purport to address all of the
3.2.1 yield stress, n—stress at fracture is used. The slope of
safety concerns, if any, associated with its use. It is the
the stress-strain curve is not required to be zero. See 7.2 for
responsibility of the user of this standard to establish appro-
reference to additional definition.
1
These test methods are under the jurisdiction of ASTM Committee D20 on
Plastics and is the direct responsibility of Subcommittee D20.10 on Mechanical
2
Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 1, 2014. Published December 2014. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
ϵ1
approved in 1990. Last previous edition approved in 1999 as D5045-99(2007) . Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D5045-14. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D5045 − 14
4. Summary of Test Methods crack orientation (parallel or perpendicular) relative to any
processing direction shall be noted on the report form dis-
4.1 These test methods involve loading a notched specimen
cussed in 10.1.
that has been pre-cracked, in either tensio
...

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.
´1
Designation: D5045 − 99 (Reapproved 2007) D5045 − 14
Standard Test Methods for
Plane-Strain Fracture Toughness and Strain Energy Release
1
Rate of Plastic Materials
This standard is issued under the fixed designation D5045; 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
ε NOTE—Reapproved with editorial changes in March 2007
1. Scope*
1.1 These test methods are designed to characterize the toughness of plastics in terms of the critical-stress-intensity factor, K ,
Ic
and the energy per unit area of crack surface or critical strain energy release rate, G , at fracture initiation.
Ic
1.2 Two testing geometries are covered by these test methods, single-edge-notch bending (SENB) and compact tension (CT).
1.3 The scheme used assumes linear elastic behavior of the cracked specimen, so certain restrictions on linearity of the
load-displacement diagram are imposed.
1.4 A state-of-plane strain at the crack tip is required. Specimen thickness must be sufficient to ensure this stress state.
1.5 The crack must be sufficiently sharp to ensure that a minimum value of toughness is obtained.
1.6 The significance of these test methods and many conditions of testing are identical to those of Test Method E399, and,
therefore, in most cases, appear here with many similarities to the metals standard. However, certain conditions and specifications
not covered in Test Method E399, but important for plastics, are included.
1.7 This protocol covers the determination of G as well, which is of particular importance for plastics.
Ic
1.8 These test methods give general information concerning the requirements for K and G testing. As with Test Method E399,
Ic Ic
two annexes are provided which give the specific requirements for testing of the SENB and CT geometries.
1.9 Test data obtained by these test methods are relevant and appropriate for use in engineering design.
1.10 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—There is currently no ISO standard that duplicates these test methods. Pending ISO/CD 13586 covers similar testing and references this test
method for testing conditions. This standard and ISO 13586 address the same subject matter, but differ in technical content.
2. Referenced Documents
2
2.1 ASTM Standards:
D638 Test Method for Tensile Properties of Plastics
D4000 Classification System for Specifying Plastic Materials
E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K of Metallic Materials
Ic
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions:
3.1.1 compact tension, n—specimen geometry consisting of single-edge notched plate loaded in tension. See 3.1.5 for reference
to additional definition.
1
These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
Current edition approved March 1, 2007Dec. 1, 2014. Published June 2007December 2014. Originally approved in 1990. Last previous edition approved in 1999 as
ϵ1
D5045 - 99.D5045 - 99(2007) . DOI: 10.1520/D5045-99R07E01.10.1520/D5045-14.
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.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D5045 − 14
3.1.2 critical strain energy release rate, G , n—toughness parameter based on energy required to fracture. See 3.1.5 for
Ic
reference to additional definition.
3.1.3 plane-strain fracture toughness, K , n—toughness parameter indicative of the resistance of a material to fracture. See
Ic
3.1.5 for reference to additional definition.
3.1.4 single-edge notched bend, n—specimen geometry consisting of center-notched beam loaded in three-point b
...