A Study of Failure Characteristics in Thermoplastic Composite Laminates Due to an Eccentric Circular Discontinuity

Abstract

The purpose of this thesis was to determine (both experimentally and analytically) the initiation and progression of failure, stress-strain response, and the failure loads of Graphite/Polyetheretherketone (Gr/PEEK) laminates, incorporating an eccentric 0.4 inch circular discontinuity, loaded in axial tension at room temperature. For each ply lay-up, three values of eccentricity were considered (the three values of eccentricity were determined by the hole location within each specimen). In addition, experimentation was conducted to study the effects of boundary conditions on the failure characteristics of the Gr/PEEK laminates; this was accomplished through the use of a special mounting fixture which allowed in-plane rotation of the specimens. Finally, experimentation was conducted, using photoelasticity, to verify the gross stress states of the Gr/PEEK laminates predicted by the analytical study. Analytically, a nonlinear material finite element program was used to predict the initiation and progression of failure, stress-strain response, and the failure loads of the Gr/Peek laminates. In addition, the effects of boundary conditions on the failure modes of the Gr/Peek laminates was studied analytically. And finally, the gross stress states of the Gr/PEEK laminates were considered in the analytical portion of this thesis.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1989
Accession Number
ADA216226

Entities

People

  • John A. Daniels

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Cyber

DTIC Thesaurus Topics

  • Composite Materials
  • Computer Programs
  • Elastic Properties
  • Finite Element Analysis
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Testing
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Micromechanics
  • Stress Strain Relations
  • Stresses
  • Thermoplastic Composites
  • Two Dimensional

Readers

  • Structural Health Monitoring of Composite Structures.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).