Analysis of Symmetric Reinforcement of Quasi-Isotropic Graphite-Epoxy Plates with a Circular Cutout under Uniaxial Tensile Loading.

Abstract

An experimental and computational analysis was made of the strain field around a reinforced circular hole in four HMF330/34 graphite/epoxy (G/Ep) panels under uniaxial tensile loading. The basic panel was a 10.0 in. wide, 26.0 in. long, eight ply, quasi-isotropic (0/+45/90)s cloth laminate. Each panel was reinforced during manufacture by co-curing two circular plies of the same material to each side of the panel. A circular one inch hole was drilled concentrically through the laminate to provide a stress concentration. The symmetric reinforcement reported here provided an improvement of 29 to 40% in ultimate strength over a similar but unreinforced panel under the same loading conditions. Test results indicated that panel failure would occur when the fibers in the dominating orientation were strained approximately 1%. There appeared to be a significant load transfer within the laminate at high strains from the failed fibers. A finite element analysis was made and found in excellent agreement with experimental results.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1983
Accession Number
ADA139998

Entities

People

  • D. H. Pickett
  • Patricia Sullivan

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aircrafts
  • Airframes
  • Composite Materials
  • Finite Element Analysis
  • Geometry
  • Graphitic Materials
  • Laminates
  • Manufacturing
  • Materials
  • Orientation (Direction)
  • Photographs
  • Plastic Explosives
  • Schools
  • Stress Concentration
  • Stresses
  • United States
  • United States Naval Academy

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Reinforced Composite Materials
  • Structural Health Monitoring of Composite Structures.