Dynamic Failure Modes for Fluid-Pressure Loaded Composite Shells.

Abstract

Specialized tools have been developed to elucidate the fundamental mechanisms driving the interaction between delamination crack tip conditions and local and global buckling modes in two dimensional problems of compressively loaded composite flat panels and cylindrical shells. Significant progress was made in understanding the interplay between the energy going into the fracture process and the structural deformation modes. For flat composite panels subjected to compressive loadings, it was found that when a delamination was above a critical length, the postbuckling behavior shifted from stable to unstable. The bifurcation eigenvectors for the composite panels have been analyzed and it was determined that they are orthogonal for cases with a stable postbuckling path and nonorthogonal (coupled) when the postbuckling load-deflection response is unstable. It thus appears that the local energy associated with a delamination crack tip provides a mechanism for coupling the local and global buckling modes of the panel when the structural flexibilities are in a critical region.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1996
Accession Number
ADA318130

Entities

People

  • Alan S. Kushner
  • Toshio Nakamura

Organizations

  • Stony Brook University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Buckling
  • Composite Materials
  • Composite Structures
  • Couplings
  • Crack Tips
  • Cracks
  • Delamination
  • Eigenvectors
  • Engineering
  • Failure Mode And Effect Analysis
  • Geometry
  • Laminates
  • Materials
  • Mechanical Properties
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Materials Science (Mechanical Engineering).
  • Structural Dynamics.
  • Structural Health Monitoring of Composite Structures.