Determination of Elastic Constants for Flawed and Unflawed Composite Tubes Using Speckle Interferometry.

Abstract

The objective of this work is to determine elastic constants for composite cylindrical specimens with and without flaws. Speckle interferometry was used to measure the displacements of 30 fiber reinforced, thin wall, composite pressure vessels. Small simulated spot flaws were introduced in 12 of the cylinders while 18 had no flaws. A mathematical and geometrical development is presented to determine the modulus of elasticity and Poisson's ratio for the composite cylinders. The test setup and procedure for preparing interferograms is described. The technique of speckel interferometric analysis using Young's Fringes is presented. A computer aided data reduction system used to analyze the interferograms is described. Plots were made of displacements versus scan points for the flawed and unflawed cylinders. The spot flaws were not detected from the displacement data. Circumferential stress, circumferential strain, axial strain, modulus of elasticity and Poisson's ratio were computed. This report presents a valid and efficient technique to determine elasticity constants using speckle interferometry. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Mar 08, 1979
Accession Number
ADA069191

Entities

People

  • Terry L. Vandiver

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Composite Materials
  • Composite Structures
  • Computer Programs
  • Computers
  • Data Analysis
  • Fibers
  • Images
  • Laser Beams
  • Measurement
  • Modulus Of Elasticity
  • Nomenclature
  • Orientation (Direction)
  • Pressure Vessels
  • Spearography
  • Thickness
  • Thin Walls
  • Translations

Readers

  • Image Processing and Computer Vision.
  • Mechanical Engineering/Mechanics of Materials.