Definitions /Dictionary/Glossary - nptel

Coupon: A specimen for a specific test, usually as a tensile coupon.
Coverage: The measure of the fraction of surface area covered by the braid.
Cowoven Fabric: It is a reinforcement fabric woven with two different types of fibers in
individual yarns; for example, thermoplastic fibers woven side by side with carbon fibers.
Crack: Actual separation of molded material, visible on opposite surfaces of the part and
extending through the thickness.
Crazing: Apparent fine cracks at or under the surface of an organic matrix.
Creel: A framework arranged to hold tows, rovings, or yarns so that many ends can be
withdrawn smoothly and evenly without tangling.
Creep: The time dependent part of strain resulting from an applied stress.
Creep, Rate Of: The slope of the creep-time curve at a given time.
Crimp: The undulations induced into a braided fabric via the braiding process.
Crimp Angle: The maximum acute angle of a single braided yarn's direction measured from the
average axis of tow.
Crimp Exchange: The process by which a system of braided yarns reaches equilibrium when
put under tension or compression.
Critical Length: The minimum length of a fiber necessary for matrix shears loading to develop
fiber ultimate strength by matrix.
Critical Value(s): When testing a one-sided statistical hypothesis, a critical value is the value
such that, if the test statistic is greater than (less than) the critical value, the hypothesis is
rejected. When testing a two-sided statistical hypothesis, two critical values are determined. If
the test statistic is either less than the smaller critical value or greater than the larger critical
value, then the hypothesis is rejected. In both cases, the critical value chosen depends on the
desired risk (often 0.05) of rejecting the hypothesis when it is true.
Cross Laminated: Material laminated so that some of the layers are oriented at various angles to
the other layers with respect to the laminate grain. A cross-ply laminate usually has plies oriented
only at [0/90].
Cross-Linking: It is the process of bridging two polymer chains, which converts a thermoplastic
to a thermoset.
Cross ply: Any filamentary laminate which is not uniaxial. This is same as Angle-ply. In some
references, the term cross-ply is used to designate only those laminates in which the laminae are