ASTM D747-10
(Test Method)Standard Test Method for Apparent Bending Modulus of Plastics by Means of a Cantilever Beam (Withdrawn 2019)
Standard Test Method for Apparent Bending Modulus of Plastics by Means of a Cantilever Beam (Withdrawn 2019)
SIGNIFICANCE AND USE
This test method provides a means of deriving the apparent bending modulus of a material by measuring force and angle of bend of a cantilever beam. The mathematical derivation assumes small deflections and purely elastic behavior. Under actual test conditions, the deformation has both elastic and plastic components. This test method does not distinguish or separate these, and hence a true elastic modulus is not calculable. Instead, an apparent value is obtained and is defined as the apparent bending modulus of the material. The tangent modulus obtained by Test Methods D790 is preferred, when the material can be tested by the Test Methods D790 test procedure.
Because of deviations from purely elastic behavior, changes in span length, width, and depth of the specimen will affect the value of the apparent bending modulus obtained; therefore, values obtained from specimens of different dimensions are not necessarily comparable.
Rate of loading is controlled only to the extent that the rate of angular change of the rotating jaw is fixed at 58 to 66°/min. Actual rate of stressing will be affected by span length, width, depth of the specimen, and weight of the pendulum.
For many materials, there are specifications that require the use of this test method, but with some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer to that material specification before using this test method. Table 1 of Classification System D4000 lists the ASTM materials standards that currently exist.
Note 2—A discussion of the theory of obtaining a purely elastic bending modulus, using a cantilever beam testing apparatus, can be found in Appendix X1. The results obtained under actual test conditions will be the apparent bending modulus.
SCOPE
1.1 This test method covers the determination of the apparent bending modulus of plastics by means of a cantilever beam. It is well suited for determining relative flexibility of materials over a wide range. It is particularly useful for materials too flexible to be tested by Test Methods D790.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 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 no known ISO equivalent to this standard.
WITHDRAWN RATIONALE
This test method covers the determination of the apparent bending modulus of plastics by means of a cantilever beam. It is well suited for determining relative flexibility of materials over a wide range. It is particularly useful for materials too flexible to be tested by Test Methods D790.
Formerly under the jurisdiction of Committee D20 on Plastics, this test method was withdrawn in January 2019 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
General Information
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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: D747 − 10
Standard Test Method for
Apparent Bending Modulus of Plastics by Means of a
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Cantilever Beam
This standard is issued under the fixed designation D747; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 3. Terminology
1.1 This test method covers the determination of the appar- 3.1 Definitions of Terms Specific to This Standard:
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ent bending modulus of plastics by means of a cantilever 3.1.1 apparent bending modulus—an apparent modulus of
beam. It is well suited for determining relative flexibility of elasticity obtained in flexure, using a cantilever beam testing
materials over a wide range. It is particularly useful for apparatus, where the deformation involved is not purely elastic
materials too flexible to be tested by Test Methods D790. but contains both elastic and plastic components.
1.2 The values stated in SI units are to be regarded as the
4. Significance and Use
standard. The values given in parentheses are for information
4.1 This test method provides a means of deriving the
only.
apparent bending modulus of a material by measuring force
1.3 This standard does not purport to address all of the
and angle of bend of a cantilever beam. The mathematical
safety concerns, if any, associated with its use. It is the
derivation assumes small deflections and purely elastic behav-
responsibility of the user of this standard to establish appro-
ior. Under actual test conditions, the deformation has both
priate safety and health practices and determine the applica-
elastic and plastic components. This test method does not
bility of regulatory limitations prior to use.
distinguish or separate these, and hence a true elastic modulus
NOTE 1—There is no known ISO equivalent to this standard.
is not calculable. Instead, an apparent value is obtained and is
defined as the apparent bending modulus of the material. The
2. Referenced Documents
tangent modulus obtained by Test Methods D790 is preferred,
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2.1 ASTM Standards:
when the material can be tested by the Test Methods D790 test
D618 Practice for Conditioning Plastics for Testing
procedure.
D790 Test Methods for Flexural Properties of Unreinforced
4.2 Because of deviations from purely elastic behavior,
and Reinforced Plastics and Electrical Insulating Materi-
changes in span length, width, and depth of the specimen will
als
affect the value of the apparent bending modulus obtained;
D4000 Classification System for Specifying Plastic Materi-
therefore, values obtained from specimens of different dimen-
als
sions are not necessarily comparable.
D5947 Test Methods for Physical Dimensions of Solid
4.3 Rate of loading is controlled only to the extent that the
Plastics Specimens
rate of angular change of the rotating jaw is fixed at 58 to
E177 Practice for Use of the Terms Precision and Bias in
66°/min. Actual rate of stressing will be affected by span
ASTM Test Methods
length, width, depth of the specimen, and weight of the
E691 Practice for Conducting an Interlaboratory Study to
pendulum.
Determine the Precision of a Test Method
4.4 For many materials, there are specifications that require
the use of this test method, but with some procedural modifi-
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This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. cations that take precedence when adhering to the specifica-
Current edition approved April 1, 2010. Published April 2010. Originally
tion. Therefore, it is advisable to refer to that material speci-
approved in 1943. Last previous edition approved in 2008 as D747 - 08. DOI:
fication before using this test method. Table 1 of Classification
10.1520/D0747-10.
2 System D4000 lists the ASTM materials standards that cur-
This property was designated stiffness in versions of this test method issued
prior to 1984.
rently exist.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
NOTE 2—A discussion of the theory of obtaining a purely elastic
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on bending modulus, using a cantilever beam testing apparatus, can be found
the ASTM website. in Appendix X1. The results obtained under actual test conditions will be
*A Summary of Changes section appears at the end of this standard
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