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System and Method for Detecting Cracks and their LocationA system and method are provided for detecting cracks and their location in a structure. A circuit coupled to a structure has capacitive strain sensors coupled sequentially and in parallel to one another. When excited by a variable magnetic field, the circuit has a resonant frequency that is different for unstrained and strained states. In terms of strained states, the resonant frequency is indicative of a region of the circuit that is experiencing strain induced by strain in a region of the structure in proximity to the region of the circuit. An inductor is electrically coupled to one end of each circuit. A magnetic field response recorder wirelessly transmits the variable magnetic field to the inductor and senses the resonant frequency of the circuit so-excited by the variable magnetic field.
Document ID
20070023494
Acquisition Source
Headquarters
Document Type
Other - Patent
Authors
Woodward, Stanley E.
(NASA Langley Research Center Hampton, VA, United States)
Shams, Qamar A.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 23, 2013
Publication Date
June 19, 2007
Subject Category
Structural Mechanics
Report/Patent Number
Patent Number: US-Patent-7,231,832
Patent Application Number: US-Patent-Appl-SN-229439
Patent Application Number: US-Patent-Appl-SN-611170
Patent Number: NASA-Case-LAR-16970-1
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-Patent-7,231,832|NASA-Case-LAR-16970-1
Patent Application
US-Patent-Appl-SN-229439|US-Patent-Appl-SN-611170
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