The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 07, 1998
Filed:
Feb. 25, 1997
Kiyoshi Tsuboi, Musashino, JP;
Shigeharu Yamamoto, Yokohama, JP;
Iwatsu Electric Co., Ltd., Tokyo, JP;
All Nippon Airways Co., Ltd., Tokyo, JP;
Abstract
A method and apparatus for detecting a change in the state of a part of an object to be measured that has a section having a first plate part and a second plate part which has a plate surface opposite to a plate surface of the first plate part with a gap between the plate surfaces and is integral with the first plate part or is connected to the first plate part. The method includes, and the apparatus has device for, applying vibrations to the object to be measured at a site at the section to generate flexural, torsional and stationary vibration waves in the object, subjecting the stationary vibration waves generated in the object to be measured to a spectral analysis, calculating the frequency difference of spectra divided into two by high order torsional vibrations generated at the section out of the group of spectra by the stationary vibration waves, and detecting a change in thickness between the first plate part and the second plate part or a defect formed in the first plate part or the second plate part based on the calculated frequency difference.