Definitions /Dictionary/Glossary - nptel

Doubler: Localized area of extra layer reinforcement, usually to provide stiffness or strength for
fastening or other abrupt load transfers.
Draft: The tape or slope of the vertical surfaces of a mold designed to facilitate removal of
molded parts.
Draft Angle: A mandrel's taper or angle for ease of part removal.
Drain Out: The leaking, sagging and puddling of the laminating resin from the laminate.
Drape: The ability of pre impregnated broad goods to conform to an irregular shape; textile
conformity.
Drawn Fibre: It is fibre with a certain amount of orientation imparted by the drawing process by
which it was formed.
Drilled Core: Honeycomb that has holes drilled in the cell walls to allow gases or fluids to
escape from the cells.
Dry: A material condition of moisture equilibrium with a surrounding environment at 5% or
lower relative humidity.
Dry Spot: Area of incomplete surface film on laminated plastics; in laminated glass, an area
over which the interlayer and the glass have not become bonded.
Dry Chop: Chopping a roving without the simultaneous admixture of resin and catalyst.
Dry Fiber Area: Area of fiber not totally encapsulated by resin.
Dry Laminate: The laminate containing insufficient resin.
Dry Lay-up: Construction of a laminate by the layering of pre-impregnating reinforcement in a
female mold or on a male mold usually followed by bag molding or autoclave molding.
Dry Winding: A type of filament winding in which pre-impregnated roving is used.
Ductility: The ability of a material to deform plastically before fracturing.
Duplication Mold: A mold made by casting over or duplicating another article.
Durometer of Hardness: The hardness of a material determined by Shore durometer.
Dwell Point: A lightning attachment point.
Dwell Time: The time that the lightning channel remains attached to a single spot Ion the
aircraft.