Experimental Mechanics

, Volume 29, Issue 2, pp 231–236 | Cite as

Real-time moiré interferometry

  • H. S. Johnson
  • J. A. Gilbert
  • D. R. Matthys
  • T. D. Dudderar


A high-frequency moiré interferometric technique to continuously monitor in-plane surface displacement is presented. This technique employs fiber optics and a thermoplastic device to holographically record the initial carrier pattern produced on the surface of a test specimen. The carrier is modulated as the specimen deforms and moiré fringes, indicative of in-plane displacement, are observed in real time. Unwanted holointerferometric patterns are eliminated by appropriately adjusting the polarization of the reference wavefront. This paper describes a demonstration of the real-time technique as applied to the study of deformations in a notched beam subjected to three-point loading.


Mechanical Engineer Fluid Dynamics Fiber Optic Test Specimen Surface Displacement 
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Copyright information

© Society for Experimental Mechanics, Inc. 1989

Authors and Affiliations

  • H. S. Johnson
    • 1
  • J. A. Gilbert
    • 1
  • D. R. Matthys
    • 2
  • T. D. Dudderar
    • 3
  1. 1.Department of Mechanical EngineeringUniversity of Alabama-HuntsvilleHuntsville
  2. 2.Department of PhysicsMarquette UniversityMilwaukee
  3. 3.Technical StaffAT&T Bell LaboratoriesMurray Hill

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