Definitions /Dictionary/Glossary - nptel

Critical length: The minimum lengths of a fiber necessary for matrix shear loading to develop
fiber ultimate strength by a matrix.
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°.
Crystallinity: The quality of having a molecular structure with atoms arranged in an orderly,
three-dimensional pattern.
Cure: To change the physical properties of a material irreversibly by chemical reaction via heat
and catalysts, alone or in combination, with or without pressure.
Cure temperature: The temperature at which a material attains final cure.
Curing agent: It is a catalytic or reactive agent that brings about polymerization when it is
added to a resin.
Damage tolerance: A measure of the ability of structures to retain load-carrying capability after
exposure to sudden loads (for example, ballistic impact).
Damping: Diminishing the intensity of vibrations.
Debond: An unplanned non-adhered or unbonded region in an assembly.
Delamination: The separation of a laminated plastic material along the plane of its layers.
Denier: A numbering system for yarn and filament in which yarn number is equal to weight in
grams of 9000 meters of yarn.
Design allowable: A limiting value for a material property that can be used to design a structural
or mechanical system to a specified level of success with 95% statistical confidence. B-basis
allowable: material property exceeds the design allowable 90 times out 100. A-basis allowable:
material property exceeds the design allowable 99 times out of 100.
Doubler: Localized area of extra layers of reinforcement, usually to provide stiffness or strength
for fastening or other abrupt load transfers.
Draft angle: A mandrel's taper or angle for ease of part removal.
Drape: The ability of prepreg to conform to the shape of a contoured surface.
Dry winding: A type of filament winding in which preimpregnated roving is used.
E-glass: "Electrical glass"; the borosilicate glass most often used for the glass fibers in
conventional reinforced plastics.