Accession Number : ADA018081

Title :   Modified Composite Structures.

Descriptive Note : Final rept.

Corporate Author : ANALY-SYN LABS INC PAOLI PA

Report Date : JUN 1975

Pagination or Media Count : 14

Abstract : One of the principal failure modes of fiber-reinforced resins is interlaminar shear. This task addresses a possible solution to this defect by linking the laminate plies with fibers inserted through the plies in a direction normal to the surface of the laminate. The present task proposes to simplify the vertical threading step in 3-D type fabric structures by a procedure akin to the 'hooking' of rugs - hereinafter described by the more generic term of 'needling'. The needling process appears entirely feasible for introducing vertical fibers in rows as close as 1/8 in. apart. Two types of standard industrial sewing machines were used, each operating without the interlocking thread reel (bobbin) beneath the machine's table. No consistent benefit from the needling treatment could be demonstrated in the cured laminates using ASTM flex and shear tests as criteria.

Descriptors :   *Fiber reinforced composites, *Composite structures, *Failure(Mechanics), *Fabrics, *Manufacturing, Shear stresses, Three dimensional, Laminates, Fabrication, Technology, Glass textiles, Nylon, Dacron

Subject Categories : Refractory Fibers
      Laminates and Composite Materials
      Textiles
      Plastics
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE