ASTM D3552-96e1

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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e1
Designation: D 3552 – 96
Test Method for
Tensile Properties of Fiber Reinforced Metal Matrix
Composites
This standard is issued under the fixed designation D 3552; 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.
e NOTE—The designation was editorially corrected by changing it from a dual designation in November 2000.
1. Scope bility of regulatory limitations prior to use.
1.1 This test method covers the determination of the tensile
2. Referenced Documents
properties of metal matrix composites reinforced by continuous
2.1 ASTM Standards:
and discontinuous high-modulus fibers. Nontraditional metal
D 3039/D 3039M Test Method for Tensile Properties of
matrix composites as stated in 1.1.6 also are covered in this test
Polymer Matrix Composite Materials
method. This test method applies to specimens loaded in a
D 3878 Terminology for High-Modulus Reinforcing Fibers
uniaxial manner tested in laboratory air at either room tem-
and Their Composites
perature or elevated temperatures. The types of metal matrix
E 4 Practices for Force Verification of Testing Machines
composites covered are:
E 8 Test Methods for Tension Testing of Metallic Materials
1.1.1 Unidirectional—Any fiber-reinforced composite with
E 83 Practice for Verification and Classification of Exten-
all fibers aligned in a single direction. Continuous or discon-
someters
tinuous reinforcing fibers, longitudinal and transverse proper-
E 177 Practice for Use of the Terms Precision and Bias in
ties.
ASTM Test Methods
1.1.2 0°/90° Balanced Crossply—A laminate composed of
E 220 Test Method for Calibration of Thermocouples by
only 0 and 90° plies. This is not necessarily symmetric,
Comparison Techniques
continuous, or discontinuous reinforcing fibers.
E 251 Test Methods for Performance Characteristics of
1.1.3 Angleply Laminate—Any balanced laminate consist-
Metallic Bonded Resistance Strain Gages
ing of 6 theta plies where theta is an acute angle with respect
E 456 Terminology Relating to Quality and Statistics
to a reference direction. Continuous reinforcing fibers without
E 1012 Practice for Verification of Specimen Alignment
0° reinforcing fibers (that is, (645)ns, (630)ns, and so forth).
Under Tensile Loading
1.1.4 Quasi-Isotropic Laminate—A balanced and symmet-
ric laminate for which a constitutive property of interest, at a
3. Terminology
given point, displays isotropic behavior in the plane of the
3.1 Definitions—Terminology D 3878 defines terms relating
laminate. Continuous reinforcing fibers with 0° reinforcing
to high-modulus fibers and their composites. Terminology E 6
fibers (that is, (0/645/90)s, (0/630)s, and so forth).
defines terms relating to mechanical testing. Terminology
1.1.5 Unoriented and Random Discontinuous Fibers.
E 456 and Practice E 177 define terms relating to statistics. In
1.1.6 Directionally Solidified Eutectic Composites.
the event of a conflict between terms, Terminology D 3878
1.2 The values stated in SI units are to be regarded as the
shall have precedence over the other standards.
standard. The values given in parentheses are provided for
3.2 Definitions of Terms Specific to This Standard:
information purposes only.
3.2.1 continuous fiber, n—a polycrystalline or amorphous
1.3 This standard does not purport to address all of the
fiber that is continuous within the sample or component or that
safety concerns, if any, associated with its use. It is the
has ends outside of the stress fields under consideration.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.04 on Annual Book of ASTM Standards, Vol 15.03.
Lamina and Laminate Test Methods. Annual Book of ASTM Standards, Vol 03.01.
Current edition approved Oct. 10, 1996. Published December 1996. Originally Annual Book of ASTM Standards, Vol 14.02.
e1 5
published as D 3552 – 77. Previous edition D 3552 – 77 (1989) . Withdrawn. See 1994 Annual Book of ASTM Standards, Vol 14.03.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 3552
3.2.2 discontinuous fiber, n—a polycrystalline or amor- sample width and thickness. For typical specimen geometries,
phous fiber that is discontinuous within the sample or compo- an instrument with an accuracy of 62.5 μm (60.0001 in.) is
nent or that has its ends inside the stress fields under consid- adequate for thickness measurement, while an instrument with
eration. an accuracy of 625 μm (60.001 in.) is adequate for width
measurement.
4. Summary of Test Method
7.2 Testing Machine, comprised of the following:
4.1 A tension specimen is mounted in the grips of a
7.2.1 Fixed Member—A fixed or essentially stationary
mechanical testing machine and monotonically loaded, in
member carrying one grip.
tension, at a constant loading rate until specimen failure occurs.
7.2.2 Movable Member—A movable member carrying a
The ultimate strength of the material can be determined from
second grip.
the maximum load carried before failure. If the coupon strain
7.2.3 Loading Mechanism—A loading mechanism for im-
is monitored with strain or displacement transducers, then the
parting to the movable member a controlled velocity with
stress-strain response of the material can be determined, from
respect to the stationary member, this velocity to be regulated
which the ultimate tensile strain, proportional limit, and tensile
as specified in Section 10.
modulus of elasticity can be derived.
7.2.4 Load Indicator—A suitable load-indicating mecha-
5. Significance and Use
nism capable of showing the total load carried by the test
5.1 This test method is designed to produce tensile property specimen. This mechanism shall be essentially free of inertia
data for material specifications, research and development, lag at the specified rate of testing and shall indicate the load
quality assurance, and structural design and analysis. Factors with an accuracy of 61 % of the indicated value, or better. The
that influence the tensile response and should be reported accuracy of the testing machine shall be verified in accordance
include the following: material, methods of material prepara- with Practice E 4. Further, the calibrated load range used for a
tion and lay-up, specimen stacking sequence, specimen prepa- particular test shall be chosen to ensure the anticipated maxi-
ration, specimen conditioning, environment of testing, speci- mum loads are between 20 to 80 % of the calibrated load range.
men alignment and gripping, speed of testing, time at This is to ensure a linear calibrated load response and protect
temperature, and volume percent reinforcement. Properties, in the load indicator from overload conditions.
the test direction, which may be obtained from this test method
7.2.5 Grips:
include the following:
7.2.5.1 General—Grip designs shall be suited to the speci-
5.1.1 Ultimate tensile strength,
mens being tested. The grip designs described in Test Methods
5.1.2 Ultimate tensile strain, and
E 8 shall be applicable but should be sized according to the
5.1.3 Tensile modulus of elasticity.
specimen dimensions.
5.1.4 Poissons ratio.
7.2.5.2 Grips for Round Specimen—The grips for round
specimens shall be standard threaded grips or split-shoulder
6. Interferences
grips with shoulder surfaces designed to mate with correspond-
6.1 Tension test data are used as the principal criteria for the
ing specimens described in Section 8. The grips shall be
engineering design in actual structural applications. Therefore,
self-aligning.
it is important to define test conditions that will produce
7.2.5.3 Grips for Flat Specimens—The grips shall be
realistic tensile properties, including statistical variation. Such
wedge-type grips or lateral pressure grips with serrated or
data will allow the design engineer to determine the most
knurled surfaces for contact with the specimen. The grips shall
appropriate and meaningful margin of safety. The following
be self-aligning; that is, they shall be attached to their respec-
test method issues will cause significant data scatter:
tive fixed and movable members in such a manner that when
6.1.1 Material and Specimen Preparation—Poor material
any load is applied, the grips will place the axis of a correctly
fabrication practices, lack of control of fiber alignment, and
mounted specimen in coincidence with the applied load direc-
damage induced by improper coupon machining are known
tion such that no significant moment is placed on the specimen
causes of high material data scatter in composites.
test section, either in the thickness or width direction. The
6.1.2 Gripping—A high percentage of grip-induced failures,
lateral pressure that is imposed by the wedge-type grips or
especially when combined with high material data scatter, is an
applied by the lateral pressure grips shall be sufficient to
indicator of specimen gripping problems.
prevent slippage between the grip face and the specimen tab
6.1.3 System Alignment—Excessive bending will cause pre-
surface without causing excessive lateral compressive damage
mature failure, as well as highly inaccurate modulus of
to the specimen. If the serrations are too coarse, emery cloth or
elasticity determination. Every effort should be made to elimi-
similar materials may be used to distribute the gripping force
nate excess bending from the test system. Bending may occur
more uniformly over a larger area of the specimen tab. The
as a result of misaligned grips or from specimens themselves if
serrations shall be maintained clean and care shall be taken to
improperly installed in the grips or out of tolerance as a result
maintain specimen alignment during installation.
of poor specimen preparation. If there is any doubt as to the
7.2.5.4 Grip Alignment—To ensure a uniform axial tensile
alignment inherent in a given test machine, then the alignment
stress state within the specimen test section, the following grip
should be checked.
alignment criteria shall be maintained. Test systems shall be
7. Apparatus
aligned according to Test Methods E 1012. The alignment
7.1 Micrometers, suitable for reading to within 1 % of the specimen shall be aligned such that the maximum percent
D 3552
bending throughout the test section, determined at an applied specimens, the taper shall not exceed 1 % in the width of the
average strain of 500 μe, shall not exceed 10 %, and the
test section. The thickness shall not be tapered. To be statisti-
maximum measured strain from any of the strain gages on the cally representative of the material, a minimum of 200 con-
alignment specimen, as a result of gripping stresses at zero
tinuous filaments, chopped fibers, or both, is suggested in
applied load, shall not exceed 50 μe.
composites that are oriented in the direction of the load.
7.2.6 Strain—Strain should be determined by means of
8.2 Flat Specimens—The standard dimensions of flat speci-
either strain gages or an extensometer.
mens are shown in Fig. 1 and are discussed in subsequent
7.2.6.1 Strain Gages—The strain gage should be not less
sections in terms of the volume fraction and placement
than 3 mm in length for the longitudinal direction and not less
geometry of the reinforcement.
than 1.5 mm in length for the transverse direction. The gages,
8.2.1 Unidirectional and Crossply Laminate Composites:
surface preparation, and bonding agents should be chosen to
8.2.1.1 Longitudinal Specimens—The test specimens for
provide for adequate performance on the subject materials and
unidirectional and crossply laminate composites tested in the
suitable strain-recording equipment shall be used.
axial direction are shown in Fig. 1, Design A, B, C, D, or E. If
7.2.6.2 Extensometers—Extensometers used for composite
necessary to transition the load into the specimen, or to prevent
specimen shall satisfy Practice E 83, Class B-1 requirements
gripping damage to the filaments near the surface, tabs can be
can be used in place of strain gages for 25-mm (1-in.) gage
bonded onto the specimen gripping section. The tab length
length specimens or exclusively for high-temperature tests
shall be long enough to provide a shear area, 2W L at each
beyond the range of strain gage applications. Extensometers T T
end of the specimen, which is large enough to transfer the
shall be calibrated periodically in accordance with Method
maximum load to the specimen. For all but the shortest
E 83.
specimen length, the radius of the curvature of the shoulder
8. Test Specimens
should be at least 25 mm (1 in.), and if practical, the edge of the
8.1 General:
shoulder should be a straight line joining the arc segment and
8.1.1 Test Specimen Size—Within the limitations of material
the corner of the tab section. The recommended standard
availability and economy, the specimens shall be sized large
designs for axial specimens of unidirectional and crossply
enough to be statistically representative of the material to
laminate composites are Designs A and B. Designs C, D, and
provide meaningful data and, where possible, large enough to
E are considered standard designs when composite material
affix strain gages or extensometers. Gage lengths incorporating
size limitations are encountered. As stated in Note 1, for
deformation-measuring devices shall be at least 13 mm ( ⁄2 in.)
size-limited panels or blanks used in materials development
in length.
studies, a nonstandard subscaled specimen (Design F) may be
used. Further size limitations (for example, whisker-reinforced
NOTE 1—Nonstandard subscaled specimen geometries are supplied for
applications in which material size limitations preclude a 13-mm ( ⁄2-in.) composite blanks) will require small specimens, and a standard
gage length. These geometries are useful in material development studies
design is not offered here. Any deviation of specimen geometry
but are not considered as a standard. Test data from these nonstandard
from the listed standards or the use of Design F (or any other
specimens shall be evaluated and reported separately in light of their size
nonstandard small specimen design) shall be noted in the data
limitation.
summary.
8.1.2 Specimen Preparation—Mechanical property deter-
8.2.1.2 Transverse Specimens—Transverse strengths of uni-
minations of metal matrix composite specimens ar
...