Tham khảo tài liệu 'composite materials handbook vol4 [us dod 2010] 4a part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | MIL-HDBK-17-4 Fiber -- A general term used to refer to filamentary materials. Often fiber is used synonymously with fiber. It is a general term for a fiber of finite length. A unit of matter either natural or manmade which forms the basic element of fabrics and other textile structures. Fiber Content -- The amount of fiber present in a composite. This is usually expressed as a percentage volume fraction or weight fraction of the composite. Fiber Count -- The number of fibers per unit width of ply present in a specified section of a composite. Fiber Direction -- The orientation or alignment of the longitudinal axis of the fiber with respect to a stated reference axis. Fiber System -- The type and arrangement of fibrous material which comprises the fiber constituent of an advanced composite. Examples of fiber systems are collimated fibers or fiber yarns woven fabric randomly oriented short-fiber ribbons random fiber mats whiskers and so on Filament -- The smallest unit of a fibrous material. The basic units formed during spinning and which are gathered into strands of fiber for use in composites . Filaments usually are of extreme length and of very small diameter. Filaments normally are not used individually. Some textile filaments can function as a yarn when they are of sufficient strength and flexibility. Filamentary Composites -- A major form of advanced composites in which the fiber constituent consists of continuous filaments. Specifically a filamentary composite is a laminate comprised of a number of laminae each of which consists of a nonwoven parallel uniaxial planar array of filaments or filament yarns embedded in the selected matrix material. Individual laminae are directionally oriented and combined into specific multiaxial laminates for application to specific envelopes of strength and stiffness requirements. Fixed Effect -- A systematic shift in a measured quantity due to a particular level change of a treatment or condition. See Volume 1 Section .
