A new three-dimensional strain analysis technique by scattered-light speckle interferometry
Abstract
By sending a narrow beam (or thin sheet) of laser light into a transparent model, speckles are created from light scattering from the particles along the beam path. If these speckles are recorded by double exposure with deformation in between, Young's fringes are generated upon Fourier transform, similar to those obtained by Burch and Tokarski, representing the local in-plane displacement vector at each and every point along the light path. By photographing this scattered-light speckle pattern from two mutually perpendicular directions normal to the path of the laser beam displacement vectors in space of any interior point can be determined. procedures are outlined to show that the state of strain at any point can be obtained by determining the displacement vectors of four corners of a small cubic element embodying the point. Examples are given to demonstrate the validity of the proposed method.
- Publication:
-
The Engineering Uses of Coherent Optics
- Pub Date:
- 1976
- Bibcode:
- 1976euco.proc..249C
- Keywords:
-
- Displacement Measurement;
- Holographic Interferometry;
- Laser Applications;
- Light Scattering;
- Speckle Patterns;
- Strain Gages;
- Coherent Light;
- Nondestructive Tests;
- Photoelastic Analysis;
- Photographic Measurement;
- Three Dimensional Motion;
- Instrumentation and Photography