Abstract: A method and apparatus for nondestructive evaluation of a structure is disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration.
Type:
Grant
Filed:
July 7, 1987
Date of Patent:
April 25, 1989
Assignee:
The United States of America as represented by the United States Department of Energy
Abstract: A method of ultrasonic flaw detection in cast stainless steel components incorporating the steps of determining the nature of the microstructure of the cast stainless steel at the site of the flaw detection measurements by ultrasonic elements independent of the component thickness at the site; choosing from a plurality of flaw detection techniques, one such technique appropriate to the nature of the microstructure as determined and detecting flaws by use of the chosen technique.
Type:
Grant
Filed:
August 29, 1986
Date of Patent:
August 2, 1988
Assignee:
The United States of America as represented by the United States Department of Energy