An Investigation of Edge Damage Development in Quasi-Isotropic Graphite Epoxy Laminates.

Abstract

This investigation describes and documents in detail the initiation, growth, and interactions of damage along the free edges of two types of graphite/epoxy fiber-reinforced composite laminates. The damage is initiated by tensile static loading of flat coupons from each type to three different stress levels. Growth of the damage was caused by tension-tension fatigue loading. The laminates that were investigated differed only by stacking sequence. The observations were made through the use of the replication technique, a method developed for the purpose of this investigation. This technique allows for three-dimensional, instantaneous recordings of the entire specimen edge while it is under maximum load. The recordings or impressions can be studied microscopically and photographed. This method provides for detail and an overall field of vision that has not been obtained in previous studies. The damage development was also monitored by two non-destructive techniques; vibrothermography and an ultrasonic-pulse echo method.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1977
Accession Number
ADA045656

Entities

People

  • David O. Stalnaker
  • Wayne W. Stinchcomb

Organizations

  • Virginia Tech

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Epoxy Laminates
  • Fiber Reinforced Composites
  • Finite Element Analysis
  • Graphitic Materials
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Testing
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Modulus Of Elasticity
  • Shear Stresses
  • Stress Strain Relations
  • Stresses

Readers

  • Structural Health Monitoring of Composite Structures.