ASTM D5448/D5448M-93
(Test Method)Standard Test Method for Inplane Shear Properties of Hoop Wound Polymer Matrix Composite Cylinders
Standard Test Method for Inplane Shear Properties of Hoop Wound Polymer Matrix Composite Cylinders
SCOPE
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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Designation: D 5448/D 5448M – 93
Standard Test Method for
Inplane Shear Properties of Hoop Wound Polymer Matrix
Composite Cylinders
This standard is issued under the fixed designation D 5448/D 5448M; 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 This test method determines the inplane shear properties
D 5450/D 5450M Test Method for Transverse Tensile Prop-
of wound polymer matrix composites reinforced by high-
erties of Hoop Wound Polymer Matrix Composite Cylin-
modulus continuous fibers. It describes testing of hoop wound
ders
(90°) cylinders in torsion for determination of inplane shear
E 4 Practices for Force Verification of Testing Machines
properties.
E 6 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
E 111 Test Method for Young’s Modulus, Tangent Modulus,
inch-pound units are shown in brackets. The values stated in
and Chord Modulus
each system are not exact equivalents; therefore, each system
E 122 Practice for Choice of Sample Size to Estimate the
must be used independently of the other. Combining values
Average Quality of a Lot or Process
from the two systems may result in nonconformance with the
E 177 Practice for Use of the Terms Precision and Bias in
test method.
ASTM Test Methods
1.3 This standard does not purport to address all of the
E 251 Test Methods for Performance Characteristics of
safety problems, if any, associated with its use. It is the
Metallic Bonded Resistance Strain Gages
responsibility of the user of this standard to establish appro-
E 456 Terminology Relating to Quality and Statistics
priate safety and health practices and determine the applica-
E 691 Practice for Conducting and Interlaboratory Study to
bility of regulatory limitations prior to use.
Determine the Precision of a Test Method
2. Referenced Documents E 1237 Guide for Installing Bonded Resistance Strain
Gages
2.1 ASTM Standards:
D 792 Test Methods for Density and Specific Gravity (Rela-
3. Terminology
tive Density) of Plastics by Displacement
3.1 Definitions—Terminology D 3878 defines terms relating
D 883 Terminology Relating to Plastics
to high-modulus fibers and their composites. Terminology
D 2584 Test Method for Ignition Loss of Cured Reinforced
D 883 defines terms relating to plastics. Terminology E 6
Resins
defines terms relating to mechanical testing. Terminology
D 2734 Test Method for Void Content of Reinforced Plas-
E 456 and Practice E 177 define terms relating to statistics. In
tics
the event of a conflict between terms, Terminology D 3878
D 3171 Test Method for Fiber Content of Resin-Matrix
4 shall have precedence over other standards.
Composites by Matrix Digestion
3.2 Description of Terms Specific to This Standard:
D 3878 Terminology Relating to High-Modulus Reinforc-
4 3.2.1 hoop wound, n—a winding of a cylindrical component
ing Fibers and Their Composites
where the filaments are circumferentially oriented.
D 5229/D 5229M Test Method for Moisture Absorption
−1 −2
3.2.2 inplane shear modulus, G [MT T ], n—the elastic
Properties and Equilibrium Conditioning of Polymer Ma- 12
shear modulus of a unidirectional material in the plane defined
trix Composite Materials
by axes parallel and perpendicular to the reinforcing fibers.
D 5449/D 5449M Test Method for Transverse Compressive
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 14.02.
This test method is under the jurisdiction of ASTM Committee D-30 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. using the following ASTM standard symbology for fundamental dimensions, 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. symbols is restricted to analytical dimensions when used with square brackets, as the
Annual Book of ASTM Standards, Vol 15.03. symbols may have other definitions when used without the brackets.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 5448/D 5448M
u
3.2.3 inplane shear strain at failure, g [nd], n—the value 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 Bonding Specimens to Test Fixtures—A high percentage
−2 −1
3.2.4 inplane shear strength, t ,[MT L ], of failures in or near the bond between the test specimen and
n—thestrength of a unidirectional material when an inplane the test fixture, especially when combined with high material
shear load is applied to the material. data scatter, is an indicator of specimen bonding problems.
3.2.5 specimen—a single part cut from a winding that meets 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
misaligned specimens in the test fixtures, or from departures of
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 ,
pair of holes at 90° intervals starting 45° from the diameter that
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—The fixture insert is circular with a center hole
6. Interferences through the thickness (SI units, see Fig. 4; inch-pound units,
see Fig. 5). Two sets of holes are placed along a concentric
6.1 Material and Specimen Preparation—Poor material
centerline. These holes align with the innermost set of holes in
fabrication practices, lack of control of fiber alignment, and
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—The adaptor is circular with a square central
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
equidistant from the adaptor center on a diameter perpendicular
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
same outer shell and insert used for the fixtures in Test Methods
D 5449/D 5449M and D 5450/D 5450M.
7.3 Testing Machine, comprised of the following:
FIG. 1 Assembly Drawing for the Shear Fixture and Specimen 7.3.1 Fixed Member—A fixed or essentially stationary
D 5448/D 5448M
FIG. 2 Outer Shell of the Shear Fixture in SI Units
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
the opposite end of the torsion specimen/fixture/adaptor assem- 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
prevent the application of axial forces or the axial load shall be parts is minimized.
limited to 5 % of the axial strength of the material. 7.4 Strain-Indicating Device—Load versus strain data shall
7.3.3 Drive Mechanism, for imparting to the movable mem- be determined by means of bonded resistance strain gages.
ber a uniform controlled angular velocity with respect to the Each strain gage shall be 6.3 mm [0.25 in.] in length. Strain
fixed member. This angular velocity is to be regulated as gage rosettes (0°/45°/90°) shall be used to correct for gage
specified in Section 9. misalignment. Gage calibration certification shall comply with
7.3.4 Load Indicator—A suitable load-indicating mecha- Test Method E 251. Some guidelines on the use of strain gages
nism capable of showing the total torsional load carried by the on composites are presented in 7.4.1-7.4.4. A general reference
D 5448/D 5448M
FIG. 3 Outer Shell for the Shear Fixture in Inch-Pound Units
on the subject is Tuttle and Brinson. heating effects on low-conductivity materials. Resistances of
7.4.1 Surface Preparation—The surface preparation of 350V or higher are preferred. Additional considerations should
fiber-reinforced composites discussed in Guide E 1237 can be given to the use of the minimum possible gage excitation
penetrate the matrix material and cause damage to the rein- voltage consistent with the desired accuracy (1 to 2 V is
forcing fibers, resulting in improper coupon failures. Reinforc- recommended) to further reduce the power consumed by the
ing fibers should not be exposed or damaged during the surface gage. Heating of the coupon by the gage may affect the
preparation process. The strain gage manufacturer should be performance of the material directly, or it may affect the
consulted regarding surface preparation guidelines and recom- indicated strain due to a difference between the gage tempera-
mended bonding agents for composites, pending the develop- ture compensation factor and the coefficient of thermal expan-
ment of a set of standard practices for strain gage installation sion of the coupon material.
surface preparation of fiber-reinforced composite materials.
7.4.3 Temperature Considerations—Consideration of some
7.4.2 Gage Resistance—Consideration should be given to
form of temperature compensation is recommended, even
the selection of gages having larger resistance to reduce
when testing at standard laboratory atmosphere. Temperature
compensation is required when testing in nonambient tempera-
ture environments.
Tuttle, M. E. and Brinson, H. F., “Resistance-Foil Strain-Gage Technology as
7.4.4 Transverse Sensitivity—Consideration should be
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. given to the transverse sensitivity of the selected strain gage.
D 5448/D 5448M
FIG. 4 Insert of the Shear Fixture in SI Units
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 E 122 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 chamber is required which 8. The length of all specimens shall be 140 mm [5.5 in.]. This
shall be capable of maintaining the required temperature to will provide a 102 mm [4.0 in.] gage
...
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