ASTM D747-02

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D747–02
Standard Test Method for
Apparent Bending Modulus of Plastics by Means of a
1
Cantilever Beam
This standard is issued under the fixed designation D 747; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* E 177 Practice for Use of the Terms Precision and Bias in
6
ASTM Test Methods
1.1 This test method covers the determination of the appar-
2
E 691 Practice for Conducting an Interlaboratory Study to
ent bending modulus of plastics by means of a cantilever
6
Determine the Precision of a Test Method
beam. It is well suited for determining relative flexibility of
materials over a wide range. It is particularly useful for
3. Terminology
materials too flexible to be tested by Test Methods D 790.
3.1 Definitions of Terms Specific to This Standard:
1.2 The values stated in SI units are to be regarded as the
3.1.1 apparent bending modulus—an apparent modulus of
standard. The values given in parentheses are for information
elasticity obtained in flexure, using a cantilever beam testing
only.
apparatus, where the deformation involved is not purely elastic
1.3 This standard does not purport to address all of the
but contains both elastic and plastic components.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety and health practices and determine the applica-
4.1 This test method provides a means of deriving the
bility of regulatory limitations prior to use.
apparent bending modulus of a material by measuring force
NOTE 1—There is no known ISO equivalent for this standard.
and angle of bend of a cantilever beam. The mathematical
derivation assumes small deflections and purely elastic behav-
2. Referenced Documents
ior. Under actual test conditions, the deformation has both
2.1 ASTM Standards:
elastic and plastic components. This test method does not
D 374 Test Methods for Thickness of Solid Electrical Insu-
distinguish or separate these, and hence a true elastic modulus
3
lation
is not calculable. Instead, an apparent value is obtained and is
4
D 618 Practice for Conditioning Plastics for Testing
defined as the apparent bending modulus of the material. The
D 790 TestMethodsforFlexuralPropertiesofUnreinforced
tangent modulus obtained by Test Methods D 790 is preferred,
and Reinforced Plastics and Electrical Insulating Materi-
when the material can be tested by theTest Methods D 790 test
4
als
procedure.
D 4000 Classification System for Specifying Plastic Mate-
4.2 Because of deviations from purely elastic behavior,
5
rials
changes in span length, width, and depth of the specimen will
D 4066 Classification System for Nylon Injection and Ex-
affect the value of the apparent bending modulus obtained;
5
trusion Materials
therefore, values obtained from specimens of different dimen-
sions may not necessarily be comparable.
1 4.3 Rate of loading is controlled only to the extent that the
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. rate of angular change of the rotating jaw is fixed at 58 to
Current edition approved April 10, 2002. Published June 2002. Originally
66°/min. Actual rate of stressing will be affected by span
published as D 747 – 43 T. Last previous edition D 747 – 99.
length, width, depth of the specimen, and weight of the
2
This property was designated stiffness in versions of this test method issued
pendulum.
prior to 1984.
3
Annual Book of ASTM Standards, Vol 10.01.
4
Annual Book of ASTM Standards, Vol 08.01.
5 6
Annual Book of ASTM Standards, Vol 08.02. Annual Book of ASTM Standards, Vol 14.02.
*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 ----------------------
D747–02
4.4 For many materials, there may be a specification that
where:
requires the use of this test method, but with some procedural
M = actual bending moment at the angle u,
w
modifications that take precedence when adhering to the
W = total applied load, N (or lbf),
specification. Therefore, it is advisable to refer to that material L = length of the pendulum arm, m (or in.), and
u = angle through which the pendulum rotates.
specification before using this test method. Table 1 of Classi-
ficationSystemD 4000liststheASTMmaterialsstandardsthat
7
NOTE 3—Auxili
...