ASTM D3878-01
(Terminology)Standard Terminology Composite Materials
Standard Terminology Composite Materials
SCOPE
1.1 These definitions cover generic terms, including terms of commercial importance, that appear in one or more standards on composites containing high-modulus (greater than 20 GPa (3 X 106 psi)) fibers.
1.2 The definitions cover, in most cases, special meanings used in the composites industry. No attempt has been made to include common meanings of the same terms as used outside the composites industry.
1.3 Definitions included have, in general, been approved as standard.
General Information
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Standards Content (Sample)
Designation: D 3878 – 01
Standard Terminology for
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Composite Materials
This standard is issued under the fixed designation D 3878; 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.
1. Scope filament catenary—the difference in length of the filaments
in a specified length of tow, end, or strand as a result of
1.1 These definitions cover generic terms, including terms
unequal tension; the tendency of some filaments in a taut
of commercial importance, that appear in one or more stan-
horizontal tow, end, or strand to sag lower than others.
dards on composites containing high-modulus (greater than
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roving catenary—the difference in length of the ends, tows,
20-GPa (3 3 10 psi)) fibers.
or strands in a specified length of roving as a result of
1.2 The definitions cover, in most cases, special meanings
unequal tension; the tendency of some ends, tows, or strands
used in the composites industry. No attempt has been made to
in a taut horizontal roving to sag lower than others.
include common meanings of the same terms as used outside
composite:
the composites industry.
composite material—a substance consisting of two or more
1.3 Definitions included have, in general, been approved as
materials, insoluble in one another, which are combined to
standard.
form a useful engineering material possessing certain prop-
2. Referenced Documents
erties not possessed by the constituents.
2.1 ASTM Standards:
DISCUSSION—a composite material is inherently inhomogeneous on a
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D 123 Terminology Relating to Textiles
microscopic scale but can often be assumed to be homogeneous on a
macroscopic scale for certain engineering applications. The constitu-
2.2 Military Standard:
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ents of a composite retain their identities: they do not dissolve or
MIL-HDBK-17
otherwise merge completely into each other, although they act in
concert.
3. Terminology
3.1 Definitions:
discontinuous fiber-reinforced composite—any composite
material consisting of a matrix reinforced by discontinuous
645° laminate—a balanced symmetric laminate composed of
fibers. The fibers may be whiskers or chopped fibers.
only +45° plies and −45° plies.
fabric-reinforced composite—any composite material con-
angleply laminate—any balanced laminate consisting of plus
sisting of a matrix reinforced by fabric (woven, knitted, or
and minus theta plies where theta is an acute angle with
braided assemblages of fibers).
respect to a reference direction.
fiber-reinforced composite—any composite material consist-
balanced laminate—any laminate that contains one ply of
ing of a matrix reinforced by continuous or discontinuous
minus theta orientation with respect to the laminate principal
fibers.
axis for every identical ply with a plus theta orientation.
filamentary composite—a composite material reinforced
braided fabric—see braided fabric under fabric.
with continuous fibers.
bundle—a general term for a collection of essentially parallel
unidirectional fiber-reinforced composite—any fiber-
filaments.
reinforced composite with all fibers aligned in a single
carbon fiber precursor—a material from which carbon fiber
direction.
is made by pyrolysis. Polyacrylonitrile, rayon or pitch fibers
crossply laminate—a laminate composed of only 0 and 90°
are commonly used precursors.
plies. This is not necessarily symmetric.
catenary:
damage, n—in structures and structural materials, an
anomaly or imperfection in a material or structure.
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These definitions are under the jurisdiction of ASTM Committee D30 on
DISCUSSION—This is a generic usage of the term covering all
Composite Materials and are the direct responsibilities of Subcommittee D30.01 on
anomalies and imperfections ranging from the material level to the
Editorial and Resource Standards.
Current edition approved Sept. 10, 2001. Published November 2001. Originally overall structural level. Specific terms that are used include defects and
published as D 3878 – 81. Last previous edition D 3878 – 00.
flaws. For example, in common (aircraft) industry usage, that which
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Annual Book of ASTM Standards, Vol 07.01.
occurs in the basic acquired material as produced is referred to as a
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Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
defect; that which occurs due to manufacturing processes is referred to
Robbins Ave., Philadelphia, PA 19111–5094.
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D 3878
TABLE 1 Fiber Forms
as a flaw; and only that which occurs due to in-service usage is
specifically referred to as damage.
Discontinuous
Continuous Filaments
Filaments
damage resistance, n—in structur
...
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