Accession Number : ADA301986

Title :   Preliminary Investigation of Crack Arrest in Composite Laminates Containing Buffer Strips.

Descriptive Note : Contractor rept.,

Corporate Author : CLEMSON UNIV SC DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Goree, James G.

PDF Url : ADA301986

Report Date : MAY 1978

Pagination or Media Count : 61

Abstract : The mechanical properties of some hybrid buffer strip laminates and the crack arrest potential of laminates containing buffer strips were determined. The hybrid laminates consisted of graphite with either S-glass, E- glass, or Kevlar. Unnotched tensile coupons and center-cracked fracture coupons were tested. Elastic properties, complete stress/strain curves, and critical stress intensity values are given. The measured elastic properties compare well with those calculated by classical lamination theory for laminates with linear stress/strain behavior. The glass hybrids had more delamination and higher fracture toughness than the all-graphite or the Kevlar hybrid. The buffer strip laminates for the crack arrest study were fabricated using six layers of woven fiberglass cloth and polyester resin. Each laminate contained two buffer strips formed by interrupting the cloth and weakening the inner laminar bond with teflon coated glass fabric. Woven Kevlar cloth was also used in some laminates in place of the fiberglass buffer strips.

Descriptors :   *CRACK PROPAGATION, *EPOXY LAMINATES, *GRAPHITE EPOXY COMPOSITES, STRESS STRAIN RELATIONS, BUFFERS, FIBERGLASS, STATIC LOADS, STRESS TESTING, TENSILE STRESS, CRACKING(FRACTURING), DAMAGE ASSESSMENT, MODULUS OF ELASTICITY, FABRICS, HYBRID SYSTEMS, DELAMINATION, NOTCH TOUGHNESS, TETRAFLUOROETHYLENE RESINS, NOTCH SENSITIVITY, POLYESTER FIBERS.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE