ASTM D5467/D5467M-97(2010)
(Test Method)Standard Test Method for Compressive Properties of Unidirectional Polymer Matrix Composites Using a Sandwich Beam
Standard Test Method for Compressive Properties of Unidirectional Polymer Matrix Composites Using a Sandwich Beam
SIGNIFICANCE AND USE
This test method is designed to produce membrane compressive property data for material specifications, research and development, quality assurance, and structural design and analysis. Factors that influence the compressive response and should therefore be reported include the following: material, methods of material and specimen preparation, specimen conditioning, environment of testing, specimen alignment, speed of testing, time at reinforcement. Properties, in the test direction, that may be obtained from this test method include:
Ultimate compressive strength,
Ultimate compressive strain,
Compressive (linear or chord) modulus of elasticity, and
Transition strain.
SCOPE
1.1 This test method covers the in-plane compressive properties of polymer matrix composite materials reinforced by high-modulus fibers in a sandwich beam configuration. The composite material forms are limited to continuous-fiber composites of unidirectional orientation. This test procedure introduces compressive load into a thin skin bonded to a thick honeycomb core with the compressive load transmitted into the sample by subjecting the beam to four-point bending.
1.2 This procedure is applicable primarily to laminates made from prepreg or similar product forms. Other product forms may require deviations from the test method.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D5467/D5467M − 97 (Reapproved 2010)
Standard Test Method for
Compressive Properties of Unidirectional Polymer Matrix
Composite Materials Using a Sandwich Beam
This standard is issued under the fixed designation D5467/D5467M; 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.
1. Scope D695Test Method for Compressive Properties of Rigid
Plastics
1.1 This test method covers the in-plane compressive prop-
D792Test Methods for Density and Specific Gravity (Rela-
erties of polymer matrix composite materials reinforced by
tive Density) of Plastics by Displacement
high-modulus fibers in a sandwich beam configuration. The
D883Terminology Relating to Plastics
composite material forms are limited to continuous-fiber com-
D2584Test Method for Ignition Loss of Cured Reinforced
posites of unidirectional orientation. This test procedure intro-
Resins
duces compressive load into a thin skin bonded to a thick
D2734TestMethodsforVoidContentofReinforcedPlastics
honeycombcorewiththecompressiveloadtransmittedintothe
D3171Test Methods for Constituent Content of Composite
sample by subjecting the beam to four-point bending.
Materials
1.2 This procedure is applicable primarily to laminates
D3410/D3410MTest Method for Compressive Properties of
made from prepreg or similar product forms. Other product
Polymer Matrix Composite Materials with Unsupported
forms may require deviations from the test method.
Gage Section by Shear Loading
D3878Terminology for Composite Materials
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in D5229/D5229MTestMethodforMoistureAbsorptionProp-
erties and Equilibrium Conditioning of Polymer Matrix
each system may not be exact equivalents; therefore, each
system shall be used independently of the other. Combining Composite Materials
E4Practices for Force Verification of Testing Machines
values from the two systems may result in non-conformance
with the standard. E6Terminology Relating to Methods of MechanicalTesting
E111Test Method for Young’s Modulus, Tangent Modulus,
1.3.1 Within the text the inch-pound units are shown in
brackets. and Chord Modulus
E122PracticeforCalculatingSampleSizetoEstimate,With
NOTE1—Additionalproceduresfordeterminingcompressiveproperties
Specified Precision, the Average for a Characteristic of a
of polymer matrix composites may be found in Test Methods D3410/
Lot or Process
D3410M and D695.
E177Practice for Use of the Terms Precision and Bias in
1.4 This standard does not purport to address all of the
ASTM Test Methods
safety concerns, if any, associated with its use. It is the
E251Test Methods for Performance Characteristics of Me-
responsibility of the user of this standard to establish appro-
tallic Bonded Resistance Strain Gages
priate safety and health practices and determine the applica-
E456Terminology Relating to Quality and Statistics
bility of regulatory limitations prior to use.
E1237Guide for Installing Bonded Resistance Strain Gages
E1309 Guide for Identification of Fiber-Reinforced
2. Referenced Documents
Polymer-Matrix Composite Materials in Databases
2.1 ASTM Standards:
E1434Guide for Recording Mechanical Test Data of Fiber-
Reinforced Composite Materials in Databases
E1471Guide for Identification of Fibers, Fillers, and Core
This test method is under the jurisdiction of ASTM Committee D30 on
Materials in Computerized Material Property Databases
Composite Materials and is the direct responsibility of Subcommittee D30.04 on
Lamina and Laminate Test Methods.
3. Terminology
Current edition approved Oct. 1, 2010. Published March 2011. Originally
3.1 Definitions—Terminology D3878 defines terms relating
approved in 1993. Last previous edition approved in 2004 as D5467/D5467M–97
(2004). DOI: 10.1520/D5467_D5467M-97R10.
to high-modulus fibers and their composites. Terminology
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
D883definestermsrelatingtoplastics.TerminologyE6defines
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
terms relating to mechanical testing. Terminology E456 and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. PracticeE177definetermsrelatingtostatistics.Intheeventof
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5467/D5467M − 97 (2010)
a conflict between terms, Terminology D3878 shall have linear portions of a bilinear stress-strain or strain-strain curve
precedence over the other terminology standards. (a transverse strain-longitudinal strain curve as used for deter-
3.2 Definitions of Terms Specific to This Standard: mining Poisson’s ratio).
3.2.1 nominal value, n—a value, existing in name only,
3.3 Symbols:
assigned to a measurable property for the purpose of conve-
3.3.1 a—distance between neutral axes of test and opposite
nient designation. Tolerances may be applied to a nominal
facesheets.
value to define an acceptable range for the property.
3.3.2 A—cross-sectional area of test facesheet.
3.2.2 orthotropic material, n—a material with a property of
3.3.3 CV—sample coefficient of variation, in percent.
interest that, at a given point, possesses three mutually perpen-
3.3.4 E —modulus of elasticity of the opposite facesheet in
dicular planes of symmetry defining the principal material o
the test direction.
coordinate system for that property.
3.3.5 E—modulus of elasticity of the test facesheet in the
3.2.3 principal material coordinate system, n—a coordinate f
test direction.
systemwithaxesthatarenormaltotheplanesofsymmetrythat
cu
exist within the material.
3.3.6 F —ultimate compressive strength.
3.2.4 reference coordinate system, n—a coordinate system
3.3.7 G —through-thickness shear modulus of elasticity.
xz
for laminated composites used to define ply orientations. One
3.3.8 h —thickness of core.
c
of the reference coordinate system axes (normally the Carte-
c
3.3.9 σ —compressive normal stress.
sian x-axis) is designated the reference axis, assigned a
position, and the ply principal axis of each ply in the laminate
4. Summary of Test Method
is referenced relative to the reference axis to define the ply
4.1 Asandwichbeamcomposedoftwofacesheetsseparated
orientation for that ply.
by a relatively deep honeycomb core, as shown in Fig. 1,is
3.2.5 specially orthotropic, adj—a description of an ortho-
loaded in four-point bending. The main component of the
tropic material as viewed in its principal material coordinate
compression test specimen is the face sheet that is loaded in
system. In laminated composites, a specially orthotropic lami-
compression during flexure, with the material direction of
nate is a balanced and symmetric laminate of the (0/90)
i j ns
interest oriented along the length of the beam. The other
family as viewed from the reference coordinate system, such
facesheetisofamaterialandsizecarefullyselectedtopreclude
that the membrane-bending coupling terms of the stress-strain
its influence on the test results. The ultimate compressive
relation are zero.
strength of the material is determined from the load at which
transition
3.2.6 transition strain, ε ,n—the strain value at the the test facesheet of the sandwich beam fails in an acceptable
mid-range of the transition region between the two essentially compression failure mode. If the specimen strain is monitored
FIG. 1 Longitudinal Compression Sandwich Beam Test Specimen
D5467/D5467M − 97 (2010)
with strain or deflection transducers then the stress-strain beamasshowninFig.1.Thefixtureshallbeinstalledbetween
responseofthematerialcanbedetermined,fromwhichcanbe thesteelplatensofthetestingmachine.Toavoidlocalcrushing
derived the compressive modulus of elasticity for this configu- or failure as a result of stress concentrations under the loading
ration. cylinders, the diameter of loading cylinders may be up to 1.5
timesthesandwichthickness,andloadingpadsmaybeneeded
5. Significance and Use
under the loading cylinders (see 11.6).
5.1 This test method is designed to produce membrane
7.3 Testing Machine—The testing machine shall be in con-
compressive property data for material specifications, research
formance with Practices E4 and shall satisfy the following
and development, quality assurance, and structural design and
requirements:
analysis. Factors that influence the compressive response and
7.3.1 Testing Machine Heads—The testing machine shall
should therefore be reported include the following: material,
have two loading heads, with at least one movable along the
methods of material and specimen preparation, specimen
testing axis.
conditioning, environment of testing, specimen alignment,
7.3.2 Drive Mechanism—The testing machine drive mecha-
speed of testing, time at reinforcement. Properties, in the test
nism shall be capable of imparting to the movable head a
direction, that may be obtained from this test method include:
controlled displacement rate with respect to the stationary
5.1.1 Ultimate compressive strength,
head. The displacement rate of the movable head shall be
5.1.2 Ultimate compressive strain,
capable of being regulated as specified in 11.3.
5.1.3 Compressive (linear or chord) modulus of elasticity,
7.3.3 Load Indicator—The testing machine load-sensing
and
device shall be capable of indicating the total load being
5.1.4 Transition strain.
carried by the test specimen. This device shall be essentially
free from inertia lag at the specified rate of testing and shall
6. Interferences
indicate the load with an accuracy over the load range(s) of
6.1 Test Method Sensitivities—Compressive strength for a
interest of within 61% of the indicated value, as specified by
single material system has been shown to differ when deter-
PracticesE4.Theloadrange(s)ofinterestmaybefairlylowfor
mined by different test methods. Such differences can be
modulus evaluation, much higher for strength evaluation, or
attributed to specimen alignment effects, specimen geometry
both, as required.
effects, and fixture effects even though efforts have been made
NOTE 2—Obtaining precision load data over a large range of interest in
to minimize these effects.
the same test, such as when both elastic modulus and ultimate load are
6.2 Material and Specimen Preparation—Compressive
being determined, place extreme requirements on the load cell and its
modulus, and especially compressive strength, are sensitive to calibration. For some equipment, a special calibration may be required.
For some combinations of material and load cell, simultaneous precision
poor material fabrication practices, damage induced by im-
measurement of both elastic modulus and ultimate strength may not be
proper coupon machining, and lack of control of fiber align-
possible, and measurement of modulus and strength may have to be
ment. Fiber alignment relative to the specimen coordinate axis
performed in separate tests using a different load cell range for each test.
should be maintained as carefully as possible, although no
7.4 Strain-Indicating Device—Strain data, if required, shall
standard procedure to insure this alignment exists. Procedures
be determined by means of strain gages.
found satisfactory include the following: fracturing a cured
7.4.1 Bonded Resistance Strain Gages—Strain gage selec-
unidirectional laminate near one edge parallel to the fiber
tion is a compromise based on the procedure and the type of
direction to establish the [0] direction or laying in small
material to be tested. Strain gages should have an active grid
filamentcounttowsofcontrastingcolorfiber(aramidincarbon
length of 3 mm [0.125 in.] or less; (1.5 mm [0.06 in.] is
laminates and carbon in aramid or glass laminates) parallel to
preferable). Gage calibration certification shall comply with
the [0] direction either as part of the prepreg production or as
TestMethodsE251.Someguidelinesontheuseofstraingages
part of panel fabrication.
on composites are presented below, with a general discussion
6.3 Calculation—Stress equations are based on beam
on the subject in Footnote 8.
theory.
7.4.1.1 Surface preparation of fiber-reinforced composites
in accordance with Practice E1237 can penetrate the matrix
7. Apparatus
material and cause damage to the reinforcing fibers, resulting
7.1 Micrometers—The micrometer(s) shall use a suitable
in improper coupon failures. Reinforcing fibers shall not be
size diameter ball-interface on irregular surfaces such as the
exposed or damaged during the surface preparation process.
bag-side of a laminate, and a flat anvil interface on machined
Consult the strain gage manufacturer regarding surface prepa-
edges or very smooth tooled surfaces. The accuracy of the
ration guidelines and recommended bonding agents for com-
instruments shall be suitable for reading to within 1% of the
posites.
sample width and thickness. For typical specimen geometries,
7.4.1.2 Select gages having larger resistances to reduce
an instrument with an accuracy of 62.5 µm [60.0001 in.] is
heating effects on low-conductivity materials. Resistances of
desirable for thickness measurement, while an instrument with
350Ωorhigherarepreferred.Usetheminimumpossiblegage
an accuracy of 625 µm [60.001 in.] is desirable for width
measurement.
Pendleton, R. P. and Tuttle, M. E., Manual on Experimental Methods for
7.2 Compressive Fixture—A fixture of four loading cylin-
Mechanical Testing of Composites, Society for Experimental Mechanics, Bethel,
ders or cylindrical supports capable of loading the sandwich CT, 1989.
D5467/D5467M − 97 (2010)
excitation voltage consistent with the desired accuracy (1 to 2 facesheetsarebondedtothecoreusingastructuraladhesiveas
V is recommended) to reduce further the power consumed by describedin8.3.1.Ifunacceptablefailuremodesforthecarbon
the gage. Heating of the coupon by the gage may affect the
reinforced coupons occur, or if alternate reinforcement fibers
performance of the material directly, or it may affect the
are to be used (glass, aramid, boron, and so forth), then
indicated strain as a result of a difference between the gage
facesheet, beam core, and overall specimen geometry shall be
temperaturecompensationfactorandthecoefficientofthermal
designed to induce compressive failure of the test facesheet.
expansion of the coupon material.
NOTE 3—If specimens are to undergo environmental conditioning to
7.4.1.3 Temperature compensation is recommended whe
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