ASTM E132-04(2010)
(Test Method)Standard Test Method for Poisson's Ratio at Room Temperature
Standard Test Method for Poisson's Ratio at Room Temperature
SIGNIFICANCE AND USE
When uniaxial force is applied to a solid, it deforms in the direction of the applied force, but also expands or contracts laterally depending on whether the force is tensile or compressive. If the solid is homogeneous and isotropic, and the material remains elastic under the action of the applied force, the lateral strain bears a constant relationship to the axial strain. This constant, called Poisson's ratio, is an intrinsic material property just like Young's modulus and Shear modulus.
Poisson's ratio is used for design of structures where all dimensional changes resulting from application of force need to be taken into account, and in the application of the generalized theory of elasticity to structural analysis.
In this test method, the value of Poisson's ratio is obtained from strains resulting from uniaxial stress only.
SCOPE
1.1 This test method covers the determination of Poisson's ratio from tension tests of structural materials at room temperature. This test method is limited to specimens of rectangular section and to materials in which and stresses at which creep is negligible compared to the strain produced immediately upon loading.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
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.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E132 − 04 (Reapproved 2010)
Standard Test Method for
Poisson’s Ratio at Room Temperature
This standard is issued under the fixed designation E132; 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 3.1.1 Poisson’s ratio—the negative of the ratio of transverse
strain to the corresponding axial strain resulting from an axial
1.1 This test method covers the determination of Poisson’s
stress below the proportional limit of the material.
ratio from tension tests of structural materials at room tem-
3.1.2 Discussion—Above the proportional limit, the ratio of
perature. This test method is limited to specimens of rectan-
transverse strain to axial strain will depend on the average
gular section and to materials in which and stresses at which
stress and on the stress range for which it is measured and,
creep is negligible compared to the strain produced immedi-
hence, should not be regarded as Poisson’s ratio. If this ratio is
ately upon loading.
reported, nevertheless, as a value of “Poisson’s ratio” for
1.2 The values stated in inch-pound units are to be regarded
stresses beyond the proportional limit, the range of stress
as standard. The values given in parentheses are mathematical
should be stated.
conversions to SI units that are provided for information only
3.1.3 Discussion—Poisson’s ratio will have more than one
and are not considered standard.
value if the material is not isotropic. Deviations from isotropy
1.3 This standard does not purport to address all of the
should be suspected if the Poisson’s ratio, µ, determined by the
safety concerns, if any, associated with its use. It is the
method described below differs significantly from that deter-
responsibility of the user of this standard to establish appro-
mined when the ratio E/G of Young’s modulus, E, to shear
priate safety and health practices and determine the applica-
modulus, G, is substituted in the following equation:
bility of regulatory limitations prior to use.
µ 5 E/2G 21 (1)
~ !
2. Referenced Documents
where E and G must be measured with greater precision
2.1 ASTM Standards:
than the precision desired in the measurement of µ.
E4 Practices for Force Verification of Testing Machines
4. Significance and Use
E6 Terminology Relating to Methods of Mechanical Testing
E8 Test Methods for Tension Testing of Metallic Materials
4.1 When uniaxial force is applied to a solid, it deforms in
E83 Practice for Verification and Classification of Exten-
the direction of the applied force, but also expands or contracts
someter Systems
laterally depending on whether the force is tensile or compres-
E111 Test Method for Young’s Modulus, Tangent Modulus,
sive. If the solid is homogeneous and isotropic, and the
and Chord Modulus
material remains elastic under the action of the applied force,
E1012 Practice for Verification of Testing Frame and Speci-
thelateralstrainbearsaconstantrelationshiptotheaxialstrain.
men Alignment Under Tensile and Compressive Axial
This constant, called Poisson’s ratio, is an intrinsic material
Force Application
property just like Young’s modulus and Shear modulus.
4.2 Poisson’s ratio is used for design of structures where all
3. Terminology
dimensional changes resulting from application of force need
3.1 Definitions:
to be taken into account, and in the application of the
generalized theory of elasticity to structural analysis.
This test method is under the jurisdiction of ASTM Committee E28 on
4.3 In this test method, the value of Poisson’s ratio is
Mechanical Testing and is the direct responsibility of Subcommittee E28.04 on
obtained from strains resulting from uniaxial stress only.
Uniaxial Testing.
Current edition approved Sept. 1, 2010. Published November 2010. Originally
5. General Considerations
approved in 1958. Last previous edition approved in 2004 as E132 – 04. DOI:
10.1520/E0132-04R10.
5.1 The accuracy of the determination of Poisson’s ratio is
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
usually limited by the accuracy of the transverse strain mea-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
surementsbecausethepercentageerrorsinthesemeasurements
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. are usually greater than in the axial strain measurements. Since
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E132 − 04 (2010)
variationinthicknessintheaxialdirection.Theotherarrangementofthree
a ratio rather than an absolute quantity is measured, it is only
pairs of extensometers, arrangement (c), provides a check on alignment.
necessary to know accurately the relative value of the calibra-
tionfactorsoftheextensometers.Also,ingeneral,thevaluesof 6.3 Alignment Devices—Grips and other devices for obtain-
the applied forces need not be accurately known. It is fre- ingandmaintainingaxialalignmentareshowninTestMethods
quently expedient to make the determination of Poisson’s ratio E8.
concurrently with determinations of Young’s modulus and the
proportional limit. 7. Test Specimens
7.1 Selection and Preparation of Specimens—Select and
6. Apparatus
prepare test specimens that are straight and uniform in thick-
6.1 Forces—Forces shall be applied either by verified dead
ness and representative of the material being tested.
weights or in a testing machine that has been calibrated in
7.2 Dimensions—The recommended specimen configura-
accordance with Practices E4.
tion has a tested length of at least five times the tested width,
6.2 Extensometers—Class B-1 extensometers or better, as
andalengthbetweenthegripsofatleastseventimesthetested
described in Practice E83, shall be used except as otherwise
width. The tested width itself is at least equal to the tested
provided in the product specifications.
thickness. The radius of the fillets of a standard rectangular
specimen is not less than the minimum width of the specimen.
NOTE 1—If exceptions are provided in the product specification so that
extensometers of types other than those covered in Practice E83 are used, The width shall be constant over the entire length where the
it may be necessary to apply corrections, for example, the correction for
extensometers are placed and for an additional distance at each
the transverse sensitivity of bonded resistance gages.
end equal to at least this width, unless otherwise provided in
6.2.1 It is recommended that at least two pairs of extensom-
the product specifications.
etersbeused—onepairformeasuringaxialstrainandtheother
7.3 Stress Relief—This test method is intended to produce
for transverse strain, with the extensometers of each pair
intrinsic materials properties.Therefore, the specimen needs to
parallel to each other and on opposite sides of the specimen.
be free of residual stresses, which may require an annealing
Additional extensometers may be used to check on alignment
procedure at T /3 for 30 min (T is the melting point of the
m m
or to obtain better average stra
...
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