ASTM D5449/D5449M-93
(Test Method)Standard Test Method for Transverse Compressive Properties of Hoop Wound Polymer Matrix Composite Cylinders
Standard Test Method for Transverse Compressive Properties of Hoop Wound Polymer Matrix Composite Cylinders
SCOPE
1.1 This test method determines the transverse compressive properties of wound polymer matrix composites reinforced by high-modulus continuous fibers. It describes testing of hoop wound (90o
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 standard.
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 5449/D 5449M – 93
Standard Test Method for
Transverse Compressive Properties of Hoop Wound
Polymer Matrix Composite Cylinders
This standard is issued under the fixed designation D 5449/D 5449M; 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 D 5450/D 5450M Test Method for Transverse Tensile Prop-
erties of Hoop Wound Polymer Matrix Composite Cylin-
1.1 This test method determines the transverse compressive
ders
properties of wound polymer matrix composites reinforced by
E 4 Practices for Force Verification of Testing Machines
high-modulus continuous fibers. It describes testing of hoop
E 6 Terminology Relating to Methods of Mechanical Test-
wound (90°) cylinders in axial compression for determination
ing
of transverse compressive properties.
E 111 Test Method for Young’s Modulus, Tangent Modulus,
1.2 The values stated in either SI units or inch-pound units
and Chord Modulus
are to be regarded separately as standard. Within the text the
E 122 Practice for Choice of Sample Size to Estimate a
inch-pound units are shown in brackets. The values stated in
Measure of Quality for a Lot or Process
each system are not exact equivalents; therefore, each system
E 132 Test Method for Poisson’s Ratio at Room Tempera-
must be used independently of the other. Combining values
ture
from the two systems may result in nonconformance with the
E 177 Practice for Use of Terms Precision and Bias in
standard.
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
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 an Interlaboratory Study to
bility of regulatory limitations prior to use.
Determine the Precision of a Test Method
2. Referenced Documents E 1237 Practice 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 Methods for Void Content of Reinforced Plas-
E 456 and Practice E 177 defines terms relating to statistics. In
tics
the event of a conflict between terms, Terminology D 3878
D 3171 Test Methods for Fiber Content of Resin-Matrix
4 shall have precedence over other standards.
Composites by Matrix Digestion
3.2 Definitions of Terms Specific to This Standard:
D 3878 Terminology Relating to High-Modulus Reinforc-
4 3.2.1 winding—an entire part completed by one winding
ing Fibers and Their Composites
operation and then cured.
D 5229/D 5229M Test Method for Moisture Absorption
3.2.2 hoop wound, n—a winding of a cylindrical component
Properties and Equilibrium Conditioning of Polymer Ma-
where the filaments are circumferentially oriented.
trix Composite Materials
3.2.3 specimen—a single part cut from a winding. Each
D 5448/D 5448M Test Method for Inplane Shear Properties
of Hoop Wound Polymer Matrix Composite Cylinders
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 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 August 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 5449/D 5449M
winding may yield several specimens. 7. Apparatus
−2 −1
3.2.4 transverse compressive modulus, E [MT L ],
7.1 Micrometers, suitable ball type for reading to within
n—the compressive elastic modulus of a unidirectional mate-
0.025 6 0.010 mm [0.001 6 0.0004 in.] of the specimen inner
rial in the direction perpendicular to the reinforcing fibers.
and outer diameters. Flat anvil-type micrometer or calipers of
uc −2 −1
3.2.5 transverse compressive strength, s , [MT L ],
22 similar resolution may be used for the overall specimen length
n—the strength of a unidirectional material when a compres-
and the gage length (the free length between the fixtures).
sive load is applied in the direction perpendicular to the
7.2 Compression Fixture—The compression fixture consists
reinforcing fibers.
of a steel outer shell and insert. An assembly drawing for these
uc
3.2.6 transverse compressive strain at failure, e [nd],
22 components and the test fixture is shown in Fig. 1.
n—the value of strain, perpendicular to the reinforcing fibers in
7.2.1 Outer Shell—The outer shell (SI units Fig. 2, English
a unidirectional material, at failure when a compressive load is
units Fig. 3) is circular with a concentric circular hollow in one
applied in the direction perpendicular to the reinforcing fibers.
face, a groove along the diameter of the other face, and a center
hole through the thickness. Along the diameter perpendicular
4. Summary of Test Method
to the groove, three pairs of small eccentric holes are placed at
4.1 A thin-walled hoop wound cylinder nominally 100 mm
three radial distances. The two outer pairs of holes are
[4 in.] in diameter and 140 mm [5 ⁄2 in.] in length is bonded
threaded. Four additional threaded holes are placed at the same
into two end fixtures. The specimen fixture assembly is
radial distance as the innermost pair of holes at 90° intervals
mounted in the testing machine and monotonically loaded in
starting 45° from the diameter that passes through the center
compression while recording load. The transverse compressive
groove.
strength can be determined from the maximum load carried
7.2.2 Insert—The fixture insert is circular with a center hole
prior to failure. If the coupon strain is monitored with strain
through the thickness (SI units Fig. 4, English units Fig. 5).
gages then the stress-strain response, the compressive strain at
Two sets of holes are placed along a concentric centerline.
failure, transverse compression modulus of elasticity, and
These holes align with the innermost set of holes in the outer
Poisson’s ratio can be derived.
shell. The set of four holes at 90° intervals are counterbored.
5. Significance and Use
The insert is fastened inside the hollow of the outer shell to
5.1 This test method is designed to produce transverse form the concentric groove used to put the specimen in the
compressive property data for material specifications, research fixture (Fig. 1).
and development, quality assurance, and structural design and 7.2.3 The outer shell and insert for the compression fixture
analysis. Factors which influence the transverse compressive are the same outer shell and insert used for the fixtures in
response and should therefore be reported are: material, standard test methods D 5448/D 5448M and D 5450/D 5450M.
method of material preparation, specimen preparation, speci-
7.3 Testing Machine, comprised of the following:
men conditioning, environment of testing, specimen alignment 7.3.1 Fixed Member—A fixed or essentially stationary
and gripping, speed of testing, void content, and fiber volume
member.
fraction. Properties in the test direction which may be obtained 7.3.2 Movable Member.
from this test method are:
7.3.3 Steel Platens, two, flat, one of which connects to the
uc
5.1.1 Transverse compressive strength, s , load-sensing device and the other at the opposite end of the
uc
5.1.2 Transverse compressive strain at failure, e ,
assembled test fixture. At least one (preferably both) of these
5.1.3 Transverse compressive modulus of elasticity, E , platens is coupled to the test machine with a swivel joint, that
and
is, a hemispherical ball on the machine that fits into a
5.1.4 Poisson’s ratio, g . hemispherical recess on one or both of the platens.
6. Interference
6.1 Material and Specimen Preparation—Poor material
fabrication practices, lack of control of fiber alignment, and
damage induced by improper coupon machining are known
causes of high material data scatter in composites.
6.2 Bonding Specimens to Test Fixtures—A high percentage
of failures in or near the bond between the test specimen and
the test fixture, especially when combined with high material
data scatter, is an indicator of specimen bonding problems.
Specimen to fixture bonding is discussed in 11.5.
6.3 System Alignment—Excessive bending may cause pre-
mature failure, as well as highly inaccurate modulus of
elasticity determination. Every effort should be made to elimi-
nate excess bending from the test system. Bending may occur
due to misaligned grips, misaligned specimens in the test
fixtures, or from departures of the specimens from tolerance
requirements. The alignment should always be checked as
FIG. 1 Assembly Drawing for the Compression Fixture and
discussed in 12.2. Specimen
D 5449/D 5449M
FIG. 2 The Outer Shell of the Compression Fixture in Metric Units
FIG. 4 The Insert of the Compression Fixture in Metric Units
FIG. 5 The Insert of the Compression Fixture in English Units
FIG. 3 The Outer Shell of the Compression Fixture in English
The accuracy of the testing machine shall be verified in
Units
accordance with Practice E 4.
7.3.4 Drive Mechanism, for imparting to the movable mem- 7.3.6 Construction Materials—The fixed member, movable
ber a uniform controlled velocity with respect to the fixed member, platens, drive mechanism, and fixtures shall be
member, this velocity to be regulated as specified in 11.6. constructed of such materials and in such proportions that the
7.3.5 Load Indicator—A suitable load-indicating mecha- total longitudinal deformation of the system contributed by
nism capable of showing the total compressive load carried by these parts is minimized.
the test specimen. This mechanism shall be essentially free of 7.4 Strain-Indicating Device—Load versus strain data shall
inertia-lag at the specified rate of testing and shall indicate the be determined by means of bonded resistance strain gages.
load within an accuracy of 61 % of the actual value, or better. Each strain gage shall be 6.3 mm [0.25 in.] in length. The
D 5449/D 5449M
FIG. 6 Test Specimen Shown with Strain Gage Configuration
specimen shall be instrumented to measure strain in both the when testing at standard laboratory atmosphere. Temperature
axial and circumferential direction to determine Poisson’s compensation is required when testing in non-ambient tem-
Ratio. Strain gage rosettes (0°/45°/90°) shall be used to correct perature environments.
for gage misalignment. Gage calibration certification shall 7.4.4 Transverse Sensitivity—Consideration should be
comply with Test Method E 251. Some guidelines on the use of given to the transverse sensitivity of the selected strain gage.
strain gages on composites are presented as follows. A general The strain gage manufacturer should be consulted for recom-
reference on the subject is Tuttle and Brinson. mendations on transverse sensitivity corrections and effects on
7.4.1 Surface Preparation—The surface preparation of composites. This is particularly important for a transversely
fiber-reinforced composites discussed in Practice E 1237 can mounted gage used to determine Poisson’s ratio.
penetrate the matrix material and cause damage to the rein- 7.5 Conditioning Chamber—When conditioning materials
forcing fibers, resulting in improper coupon failures. Reinforc- at non-laboratory environments, a temperature/vapor-level
ing fibers should not be exposed or damaged during the surface controlled environment conditioning chamber is required
preparation process. The strain gage manufacturer should be which shall be capable of maintaining the required temperature
consulted regarding surface preparation guidelines and recom- to within 63°C [65°F] and the required relative vapor level to
mended bonding agents for composites, pending the develop- within 63 %. Chamber conditions shall be monitored either on
ment of a set of standard practices for strain-gage installation an automated continuous basis or on a manual basis at regular
surface preparation of fiber-reinforced composite materials. intervals.
7.4.2 Gage Resistance—Consideration should be given to 7.6 Environmental Test Chamber—An environmental test
the selection of gages having larger resistance to reduce chamber is required for testing environments other than ambi-
heating effects on low-conductivity materials. Resistances of ent testing laboratory conditions. This chamber shall be ca-
350 V or higher are preferred. Additional considerations pable of maintaining the gage section of the test specimen at
should be given to the use of the minimum possible gage the required test environment during the mechanical test.
excitation voltage consistent with the desired accuracy (1 to 2
8. Sampling and Test Specimens
volts is recommended) to further reduce the power consumed
8.1 Sampling—At least five specimens per test condition
by the gage. Heating of the coupon by the gage may affect the
should be tested unless valid results can be gained through the
performance of the material directly, or it may affect the
use of fewer specimens, such as in the case of a designed
indicated strain due to a difference between the gage tempera-
experiment. For statistically significant data the procedures
ture compensation factor and the coeffi
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