Astm D 3878 – 04a pdf free download

Standard Terminology for
Composite Materials1

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 the 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

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 3 106 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.

2. Referenced Documents

2.1 ASTM Standards: 2
D 123 Terminology Relating to Textiles
2.2 Military Standard:
MIL-HDBK-173

3. Terminology

3.1 Definitions: 645° laminate—a balanced symmetric laminate composed of
only +45° plies and −45° plies.
angle ply laminate—any balanced laminate consisting of plus
and minus theta plies where theta is an acute angle with
respect to a reference direction.
balanced laminate—any laminate that contains one ply of
minus theta orientation with respect to the laminate principal
axis for every identical ply with a plus theta orientation.
braided fabric—see braided fabric under the fabric.