New Optical Method to Determine Vibration-Induced Strains with Variable Sensitivity after Recording,

Abstract

A steady-state vibrating object is illuminated with coherent light and its image is slightly misfocused in the film plane of a camera. The resulting processed film is called a 'Time-integrated specklegram'. When the specklegram is Fourier filtered, it exhibits fringes depicting derivatives of the vibrational amplitude. The direction of the spatial derivative, as well as the fringe sensitivity may be easily and continuously varied during Fourier filtering process. Besides the above mentioned advantages, this new method is also much less demanding than hologrphic interferometry with respect to vibration isolation, optical set-up time, illuminating source coherence, required film resolution, etc. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1976
Accession Number
ADA032087

Entities

People

  • Augusto J. Durelli
  • J. D. Hovanesian
  • Y. Y. Hung

Organizations

  • Oakland University

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Amplitude
  • Engineering
  • Equations
  • Filtration
  • Frequency
  • Intensity
  • Interferometry
  • Lasers
  • Materials
  • Measurement
  • Mechanics
  • New York
  • Physics Laboratories
  • Propellant Grains
  • Solid Propellants
  • Strain Gages
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Image Processing and Computer Vision.
  • Optical Physics and Photonics.