continuous fibres (rus. волокна, непрерывные) — structural fibres whose length allows to neglect the end effects when they are loaded in the composites and to use them in continuous composite manufacturing processes.

Description

The main geometrical parameter of the fibre that determines its effectiveness in composite structures is the dimensionless length  equal to the ratio of the fibre length to its diameter or to the characteristic size of its cross-section (for non-circular fibres).

The critical value of the dimensionless length is the fibre length:
,

where is the fibre tensile strength which, generally, depends on its length, and is the interface shear strength. In the case of an ideal adhesive bond at the interface the value is equal to the matrix shear strength. To ignore the end effects, the following condition shall be met : For high-strength fibres ( ≈ 100. In composites with metal matrix the critical dimensionless fibre length can be smaller by an order of magnitude.

The continuity of the fibre in the technological sense means the possibility of its use in continuous processes in the manufacture of composite products, such as winding, making two-and three-dimensional fabrics, pultrusion, etc. In this case, the criterion of continuity is the absolute length of the fibre on the spool, corresponding to a specific process of manufacturing composite structural elements.

Author

  • Mileiko Sergey T.

Sources

  1. Concise Encyclopedia of Composite Materials / Ed. by A. Kelly. — Elsevier Science, 1994. — 378 p.
  2. Handbook of Composites. V. 4 / Ed. by A. Kelly, S. T. Mileiko. — NorthHolland, Amsterdam, 1983.
  3. Composite materials. Handbook Ed. by V.V. Vasil'eva, Ju. M. Tarnopol'skij (in Russian). — Moscow: Mashinostroenie, 1990. — 510 pp.

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