Numerical Determination of the Effects of Boundary Conditions on the Instability of Composite Panels with Cutouts.

Abstract

An analytical study using the STAGSC-1 computer code was conducted to determine the effects of notches and unsymmetric boundary conditions on the load bearing capability and radial displacements of axially loaded cylindrical panels. The graphite-epoxy panel consisted of an 8 ply laminate with symmetric ply orientations. A finite element mesh refinement in the vicinity of the cutout was conducted in order to study the non-linear collapse analysis. In addition, the effect of different size cutouts with aspect ratios (axial dimension of cutout divided by circumferential dimension) of 2.0 or 0.5 was studied. Finally, analytic results for a 2 in. x 2 in. cutout with a varying set of boundary conditions were compared to experimental findings. It was found that as the surface area of the cutout increased, the buckling load decreased. Cutouts with aspect ratios of 2.0 were found to be capable of carrying higher loads than notches with an aspect ratio of 0.5. By comparing analytic results with experimental data, it was found that unsymmetric boundary conditions for the 2 in. x 2 in. cutout better approximated experimental data than when symmetric boundary conditions were considered.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1983
Accession Number
ADA136772

Entities

People

  • C. E. Lee

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Composite Materials
  • Computer Programs
  • Computers
  • Coordinate Systems
  • Engineering
  • Epoxy Composites
  • Experimental Data
  • Finite Element Analysis
  • Graphite Epoxy Composites
  • Graphitic Materials
  • Laminates
  • Materials
  • Mechanics
  • Nonlinear Analysis
  • Security
  • Shape
  • Stress Strain Relations

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Structural Health Monitoring of Composite Structures.