ASTM D3878-20b

Standard Terminology for 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 × 10 6 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.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 30-Sep-2020
• ICS: 01.040.49 - Aircraft and space vehicle engineering (Vocabularies)
• ICS: 49.025.60 - Textiles
• Technical Committee: D30 - Composite Materials
• Drafting Committee: D30.01 - Editorial and Resource Standards

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D3878 − 20b
Standard Terminology for
1
Composite Materials
This standard is issued under the fixed designation D3878; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope balanced laminate, n—a laminate that contains one ply with a
ply orientation of minus theta for every ply of the same
1.1 These definitions cover generic terms, including terms
material and thickness with a ply orientation of plus theta.
of commercial importance, that appear in one or more stan-
dards on composites containing high-modulus (greater than
bond, n—the act of adhering one surface to another, with or
6
20 GPa (3 × 10 psi)) fibers.
without the use of an adhesive at the interface.
1.2 The definitions cover, in most cases, special meanings
co-cure, cocure—see cure.
used in the composites industry. No attempt has been made to
co-bond, cobond, n—the act of curing (or consolidating) and
include common meanings of the same terms as used outside
bonding one semi-solid detail (for example, uncured thermoset
the composites industry.
polymer or a thermoplastic polymer) to a solid detail in a single
process through principal action of the matrix, possibly with
1.3 Definitions included have, in general, been approved as
the inclusion of a separate layer of adhesive at the interface.
standard.
secondary bond, n—the act of bonding two or more already-
1.4 This international standard was developed in accor-
cured thermoset composite or other solid details, during which
dance with internationally recognized principles on standard-
the only chemical or thermal reaction, or both, occurring is the
ization established in the Decision on Principles for the
curing of the adhesive layer at the interface.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
DISCUSSION—For example, a previously cured composite or metal
Barriers to Trade (TBT) Committee.
doubler bonded via an adhesive to a previously cured skin, or a
previously cured face sheet bonded via an adhesive to a honeycomb
2. Referenced Documents
core. Also applies to bonding metallic substrates such as aluminum face
2
sheets onto aluminum honeycomb core.
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
braided fabric—see braided fabric under fabric.
3
2.2 Industry Standard:
breather string, n—a string, composed of a material such as
CMH-17 Composite Materials Handbook
glass, that provides a vacuum path from the laminate to a
3. Terminology
breather.
3.1 Definitions:
bundle, n—a general term for a collection of essentially
645° laminate, n—a balanced and symmetric laminate con-
parallel filaments.
sisting of plies with ply orientations of only +45° and −45°.
carbon fiber precursor, n—a material from which carbon fiber
angleply laminate, n—a balanced laminate consisting of plies
is made by pyrolysis.
with ply orientations of only plus theta and minus theta.
DISCUSSION—Polyacrylonitrile, rayon, or pitch fibers are commonly
used precursors.
1
This terminology is under the jurisdiction of ASTM Committee D30 on
catenary:
Composite Materials and is the direct responsibility of Subcommittee D30.01 on
filament catenary, n—the difference in length of the fila-
Editorial and Resource Standards.
ments in a specified length of tow, end, or strand as a result of
Current edition approved Oct. 1, 2020. Published October 2020. Originally
approved in 1981. Last previous edition approved in 2020 as D3878 – 20a. DOI:
unequal tension; the tendency of some filaments in a taut
10.1520/D3878-20B.
horizontal tow, end, or strand to sag lower than others.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
roving catenary, n—the difference in length of the ends,
Standards volume information, refer to the standard’s Document Summary page on
tows, or strands in a specified length of roving as a result of
the ASTM website.
3 unequal tension; the tendency of some ends, tows, or strands in
Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,
PA 15096, http://www.sae.org. a taut horizontal roving to sag lower than others.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D3878 − 20b
tube, and dovetail. Honeycomb core materials exhibit anisotropic
caul, n—a flat or contoured tool used to distribute pressu
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3878 − 20a D3878 − 20b
Standard Terminology for
1
Composite Materials
This standard is issued under the fixed designation D3878; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 These definitions cover generic terms, including terms of commercial importance, that appear in one or more standards on
6
composites containing high-modulus (greater than 20 GPa (3 × 10 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.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
3
2.2 Industry Standard:
CMH-17 Composite Materials Handbook
3. Terminology
3.1 Definitions:
645° laminate, n—a balanced and symmetric laminate consisting of plies with ply orientations of only +45° and −45°.
angleply laminate, n—a balanced laminate consisting of plies with ply orientations of only plus theta and minus theta.
balanced laminate, n—a laminate that contains one ply with a ply orientation of minus theta for every ply of the same material
and thickness with a ply orientation of plus theta.
1
This terminology is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.01 on Editorial and
Resource Standards.
Current edition approved May 1, 2020Oct. 1, 2020. Published May 2020October 2020. Originally approved in 1981. Last previous edition approved in 2020 as
D3878 – 20.D3878 – 20a. DOI: 10.1520/D3878-20A.10.1520/D3878-20B.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale, PA 15096, http://www.sae.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3878 − 20b
bond, n—the act of adhering one surface to another, with or without the use of an adhesive at the interface.
co-cure, cocure—see cure.
co-bond, cobond, n—the act of curing (or consolidating) and bonding one semi-solid detail (for example, uncured thermoset
polymer or a thermoplastic polymer) to a solid detail in a single process through principal action of the matrix, possibly with the
inclusion of a separate layer of adhesive at the interface.
secondary bond, n—the act of bonding two or more already-cured thermoset composite or other solid details, during which the
only chemical or thermal reaction, or both, occurring is the curing of the adhesive layer at the interface.
DISCUSSION—
For example, a previously cured composite or metal doubler bonded via an adhesive to a previously cured skin, or a previously cured face sheet bonded
via an adhesive to a honeycomb core. Also applies to bonding metallic substrates such as aluminum face sheets onto aluminum honeycomb core.
braided fabric—see braided fabric under fabric.
breather string, n—a string, composed of a material such as glass, that provides a vacuum path from the laminate to a breather.
bundle, n—a general term for a collection of essentially parallel filaments.
carbon fiber precursor, n—a material from which carbon fiber is made by pyrolysis.
DISCUSSION—
Polyacrylonitrile, rayon, or pitch fibers are commonly used precursors.
catenary:
filament catenary, n—the difference in length of the filaments in a specified length of tow, end, or strand as a result of unequal
tension; the tendency of some filaments in a taut horizontal tow, end, or strand to sag lower than others.
roving catenary, n—the difference in length o
...