Radiographic Moire
Abstract
A method for the x-ray inspection of materials making use of the Moire effect is described. The Moire effect results when two patterns are superimposed; a third pattern is produced. Any change in either of the first two patterns creates a change in the third. Moire inspection is common with visible light. This invention allows the technique to be extended to locations inaccessible to visual inspection. A first pattern of high radio contrast material is attached to or included in the sample. X-rays are projected through the sample. A second pattern is imposed at the observation point, either before or after the formation of the x-ray image. The two patterns interact to create a third, Moire, pattern. As the material is stressed the Moire pattern changes, the degree of change indicating the degree of stress.
- Publication:
-
National Aeronautics and Space Administration Report
- Pub Date:
- May 1994
- Bibcode:
- 1994nasa.reptW....M
- Keywords:
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- Moire Effects;
- Radiography;
- Stress Measurement;
- X Ray Inspection;
- Nondestructive Tests;
- Patent Applications;
- Strain Measurement;
- Quality Assurance and Reliability