Standard Test Method for Inplane Shear Properties of Hoop Wound Polymer Matrix Composite Cylinders

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1.1 This test method determines the inplane shear properties of wound polymer matrix composites reinforced by high-modulus continuous fibers. It describes testing of hoop wound (90°) cylinders in torsion for determination of inplane shear properties.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the test method.
1.3 This standard does not purport to address all of the safety problems, 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.

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ASTM D5448/D5448M-93(2000) - Standard Test Method for Inplane Shear Properties of Hoop Wound Polymer Matrix Composite Cylinders
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
Designation: D 5448/D 5448M – 93 (Reapproved 2000)
Standard Test Method for
Inplane Shear Properties of Hoop Wound Polymer Matrix
Composite Cylinders
This standard is issued under the fixed designation D5448/D5448M; 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.
1. Scope Properties of Hoop Wound Polymer Matrix Composite
Cylinders
1.1 Thistestmethoddeterminestheinplaneshearproperties
D 5450/D 5450M Test Method for Transverse Tensile
of wound polymer matrix composites reinforced by high-
Properties of Hoop Wound Polymer Matrix Composite
modulus continuous fibers. It describes testing of hoop wound
Cylinders
(90°) cylinders in torsion for determination of inplane shear
E4 Practices for Force Verification of Testing Machines
properties.
E6 Terminology Relating to Methods of Mechanical Test-
1.2 The values stated in either SI units or inch-pound units
ing
are to be regarded separately as standard. Within the text the
E111 TestMethodforYoung’sModulus,TangentModulus,
inch-pound units are shown in brackets. The values stated in
and Chord Modulus
each system are not exact equivalents; therefore, each system
E122 PracticeforCalculatingSampleSizetoEstimatewith
must be used independently of the other. Combining values
a Specified Tolerable Error, theAverage for a Characteris-
from the two systems may result in nonconformance with the
tic of a Lot or Process
test method.
E177 Practice for Use of the Terms Precision and Bias in
1.3 This standard does not purport to address all of the
ASTM Test Methods
safety problems, if any, associated with its use. It is the
E251 Test Methods for Performance Characteristics of
responsibility of the user of this standard to establish appro-
Metallic Bonded Resistance Strain Gages
priate safety and health practices and determine the applica-
E456 Terminology Relating to Quality and Statistics
bility of regulatory limitations prior to use.
E691 Practice for Conducting and Interlaboratory Study to
2. Referenced Documents Determine the Precision of a Test Method
E 1237 Guide for Installing Bonded Resistance Strain
2.1 ASTM Standards:
Gages
D792 TestMethodsforDensityandSpecificGravity(Rela-
tive Density) of Plastics by Displacement
3. Terminology
D883 Terminology Relating to Plastics
3.1 Definitions—TerminologyD3878definestermsrelating
D2584 Test Method for Ignition Loss of Cured Reinforced
3 to high-modulus fibers and their composites. Terminology
Resins
D883 defines terms relating to plastics. Terminology E6
D2734 Test Method for Void Content of Reinforced Plas-
3 defines terms relating to mechanical testing. Terminology
tics
E456 and Practice E177 define terms relating to statistics. In
D3171 Test Method for Constituent Content of Composite
4 the event of a conflict between terms, Terminology D3878
Materials
shall have precedence over other standards.
D3878 Terminology for Composite Materials
3.2 Description of Terms Specific to This Standard:
D5229/D5229M Test Method for Moisture Absorption
3.2.1 hoopwound,n—awindingofacylindricalcomponent
Properties and Equilibrium Conditioning of Polymer Ma-
where the filaments are circumferentially oriented.
trix Composite Materials
D5449/D5449M TestMethodforTransverseCompressive
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 14.02.
1 7
This test method is under the jurisdiction of ASTM Committee D30 on High If the term represents a physical quantity, its analytical dimensions are stated
Modulus Fibers and Their Composites and is the direct responsibility of Subcom- immediately following the term (or letter symbol) in fundamental dimension form,
mittee D30.04 on Lamina and Laminate Test Methods. usingthefollowingASTMstandardsymbologyforfundamentaldimensions,shown
Current edition approved Aug. 15, 1993. Published October 1993. within square brackets: [M] for mass, [L] for length, [T] for time, [u] for
Annual Book of ASTM Standards, Vol 08.01. thermodynamic temperature, and [ nd] for nondimensional quantities. Use of these
Annual Book of ASTM Standards, Vol 08.02. symbolsisrestrictedtoanalyticaldimensionswhenusedwithsquarebrackets,asthe
Annual Book of ASTM Standards, Vol 15.03. symbols may have other definitions when used without the brackets.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5448/D 5448M – 93 (2000)
−1 −2
3.2.2 inplaneshearmodulus,G [MT T ],n—theelastic 6. Interferences
shear modulus of a unidirectional material in the plane defined
6.1 Material and Specimen Preparation—Poor material
by axes parallel and perpendicular to the reinforcing fibers.
fabrication practices, lack of control of fiber alignment, and
u
3.2.3 inplaneshearstrainatfailure, g [nd],n—thevalue
damage induced by improper coupon machining are known
of inplane shear strain at failure when an inplane shear load is
causes of high material data scatter in composites.
applied to the material.
6.2 BondingSpecimenstoTestFixtures—Ahighpercentage
−2 −1
3.2.4 inplane shear strength, t ,[ MT L ], n—the
of failures in or near the bond between the test specimen and
strengthofaunidirectionalmaterialwhenaninplaneshearload
the test fixture, especially when combined with high material
is applied to the material.
data scatter, is an indicator of specimen bonding problems.
3.2.5 specimen—asinglepartcutfromawindingthatmeets
Specimen-to-fixture bonding is discussed in 11.5.
the specifications of Fig. 1. Each winding may yield several
6.3 System Alignment—Excessive bending or axial loading
specimens.
will cause premature failure, as well as highly inaccurate shear
3.2.6 winding—an entire part completed by one winding
modulus determination. Every effort should be made to elimi-
operation and then cured.
nate excess bending and axial loading from the test system.
Bending and axial loading may occur due to misaligned grips,
4. Summary of Test Method
misalignedspecimensinthetestfixtures,orfromdeparturesof
4.1 A thin walled hoop wound cylinder nominally 100 mm
the specimens from tolerance requirements. The alignment
[4 in.] in diameter and 140 mm [5 ⁄2 in.] in length is bonded
should always be checked as discussed in 12.2.
into two end fixtures. The specimen/fixture assembly is
mounted in the testing machine and monotonically loaded in
7. Apparatus
inplane shear while recording load. The inplane shear strength
7.1 Micrometers, suitable ball type for reading to within
can be determined from the maximum load carried prior to
0.025 6 0.010 mm [0.001 6 0.0004 in.] of the specimen inner
failure. If the cylinder strain is monitored with strain gages
and outer diameters. Flat anvil type or micrometer calipers of
then the stress-strain response, the inplane shear strain at
similar resolution may be used for the overall specimen length
failure, and the inplane shear modulus can be derived.
and the gage length (the free length between the fixtures).
7.2 Inplane Shear Fixture—The inplane shear fixture con-
5. Significance and Use
sists of a steel outer shell, insert, and adaptor. An assembly
5.1 This test method is designed to produce inplane shear
drawing for these components and the test fixture is shown in
property data for material specifications, research and devel-
Fig. 1.
opment, quality assurance, and structural design and analysis.
7.2.1 Outer Shell—The outer shell (SI units, see Fig. 2;
Factors that influence the inplane shear response and should
inch-pound units, see Fig. 3) is circular with a concentric
therefore be reported are material, method of material prepa-
circular hollow in one face, a groove along the diameter of the
ration, specimen preparation, specimen conditioning, environ-
other face, and a center hole through the thickness. Along the
ment of testing, specimen alignment and gripping, speed of
diameter perpendicular to the groove, three pairs of small
testing, void content, and fiber volume fraction. Properties, in
eccentric holes are placed at three radial distances. The two
the test direction, that may be obtained from this test method
outer pairs of holes are threaded. Four additional threaded
are as follows:
holes are placed at the same radial distance as the innermost
u
5.1.1 Inplane Shear Strength, t ,
pairofholesat90°intervalsstarting45°fromthediameterthat
u
5.1.2 Inplane Shear Strain at Failure, g , and
passes through the center groove.
5.1.3 Inplane Shear Modulus, G .
7.2.2 Insert—Thefixtureinsertiscircularwithacenterhole
through the thickness (SI units, see Fig. 4; inch-pound units,
see Fig. 5). Two sets of holes are placed along a concentric
centerline.These holes align with the innermost set of holes in
the outer shell. The set of 4 holes at 90° intervals are
counterbored. The insert is fastened inside the hollow of the
outer shell to form the concentric groove used to put the
specimen in the fixture.
7.2.3 Adaptor—Theadaptoriscircularwithasquarecentral
torque nut raising out of one face, a flange along a diameter on
the other face, and a central hole (SI units, see Fig. 6;
inch-pound units, see Fig. 7). Two bolt holes are placed
equidistantfromtheadaptorcenteronadiameterperpendicular
to the centerline of the flange. The adaptor is fastened to the
outer shell.The flange of the adaptor fits into the groove of the
outer shell. The complete inplane shear specimen/fixture as-
sembly is seen in Fig. 1.
NOTE 1—The outer shell and insert for the compression fixture are the
FIG. 1 Assembly Drawing for the Shear Fixture and Specimen same outer shell and insert used for the fixtures in Test Methods
D 5448/D 5448M – 93 (2000)
FIG. 2 Outer Shell of the Shear Fixture in SI Units
D5449/D5449M and D5450/D5450M.
fixed member. This angular velocity is to be regulated as
specified in Section 9.
7.3 Testing Machine, comprised of the following:
7.3.4 Load Indicator—A suitable load-indicating mecha-
7.3.1 Fixed Member—A fixed or essentially stationary
nism capable of showing the total torsional load carried by the
member, with respect to rotation, to which one end of the
test specimen. This mechanism shall be essentially free of
torsion specimen/fixture/adaptor assembly, shown in Fig. 3,
inertia-lag at the specified rate of testing and shall indicate the
can be attached.
load within an accuracy of 61% of the actual value, or better.
7.3.2 Rotational Member—A rotational member to which
7.3.5 Construction Materials—The fixed member, movable
theoppositeendofthetorsionspecimen/fixture/adaptorassem-
member, drive mechanism, fixtures, and adaptors shall be
bly, shown in Fig. 1, can be attached. Either the rotational
constructed of such materials and in such proportions that the
member or the fixed member shall be free to move axially to
total rotational deformation of the system contributed by these
preventtheapplicationofaxialforcesortheaxialloadshallbe
parts is minimized.
limited to 5% of the axial strength of the material.
7.3.3 Drive Mechanism, for imparting to the movable mem- 7.4 Strain-Indicating Device—Load versus strain data shall
ber a uniform controlled angular velocity with respect to the be determined by means of bonded resistance strain gages.
D 5448/D 5448M – 93 (2000)
FIG. 3 Outer Shell for the Shear Fixture in Inch-Pound Units
Each strain gage shall be 6.3 mm [0.25 in.] in length. Strain consulted regarding surface preparation guidelines and recom-
gage rosettes (0°/45°/90°) shall be used to correct for gage
mended bonding agents for composites, pending the develop-
misalignment. Gage calibration certification shall comply with ment of a set of standard practices for strain gage installation
Test Method E251. Some guidelines on the use of strain gages
surface preparation of fiber-reinforced composite materials.
oncompositesarepresentedin7.4.1-7.4.4.Ageneralreference
7.4.2 Gage Resistance—Consideration should be given to
on the subject is Tuttle and Brinson.
the selection of gages having larger resistance to reduce
7.4.1 Surface Preparation—The surface preparation of
heating effects on low-conductivity materials. Resistances of
fiber-reinforced composites discussed in Guide E1237 can
350Vorhigherarepreferred.Additionalconsiderationsshould
penetrate the matrix material and cause damage to the rein-
be given to the use of the minimum possible gage excitation
forcing fibers, resulting in improper coupon failures. Reinforc-
voltage consistent with the desired accuracy (1 to 2 V is
ingfibersshouldnotbeexposedordamagedduringthesurface
recommended) to further reduce the power consumed by the
preparation process. The strain gage manufacturer should be
gage. Heating of the coupon by the gage may affect the
performance of the material directly, or it may affect the
indicated strain due to a difference between the gage tempera-
Tuttle, M. E. and Brinson, H. F., “Resistance-Foil Strain-Gage Technology as
ture compensation factor and the coefficient of thermal expan-
Applied to Composite Materials,” Experimental Mechanics, Vol 24, No. 1, March
1984, pp. 54–64; errata noted in Vol 26, No. 2, January 1986, pp. 153–154. sion of the coupon material.
D 5448/D 5448M – 93 (2000)
FIG. 4 Insert of the Shear Fixture in SI Units
7.4.3 Temperature Considerations—Consideration of some ent testing laboratory conditions. This chamber shall be ca-
form of temperature compensation is recommended, even pable of maintaining the gage section of the test specimen at
when testing at standard laboratory atmosphere. Temperature
the required test environment during the mechanical test.
compensationisrequiredwhentestinginnonambienttempera-
ture environments.
8. Sampling and Test Specimens
7.4.4 Transverse Sensitivity—Consideration should be
8.1 Sampling—At least five specimens per test condition
given to the transverse sensitivity of the selected strain gage.
should be tested unless valid results can be gained through the
The strain gage manufacturer should be consulted for recom-
use of fewer specimens, such as in the case of a designed
mendations on transverse sensitivity corrections and effects on
experiment. For statistically significant data, the procedures
composites.
outlined in Practice E122 should be consulted. The method of
7.5 Conditioning Chamber—When conditioning materials
sampling shall be reported.
at nonlaboratory environments, a temperature/vapor-level con-
8.2 Geometry—The test specimen shall be as shown in Fig.
trolled environment conditioning chambe
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