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Accession Number ADA566383
Title Embedded Ultrasonics for SHM of Space Applications.
Publication Date Jul 2012
Media Count 118p
Personal Author A. N. Zagrai
Abstract The project explores application of embedded ultrasonics for monitoring integrity of space structures. Particular attention is given to the acoustic-elastic method for assessing the condition of bolted joints. The utility of the method is demonstrated for bolted structures of simple and complex geometries. The method allows for locating a loose bolt based on temporal variation of signal phase and, in structures of simple geometry, inferring correlation between torque on a bolt and associated shift in the phase of the elastic wave. A baseline-free acousto-elastic method was developed and validated on several representative structures. The opportunity to infer material parameters and boundary condition variations from embedded ultrasonic tests is highlighted. Acousto-elastic detection of a loose bolt is validated in tests involving the Plug and Play satellite and a suborbital payload. Sensor statistics and shielding are considered. It is advocated that the acousto- elastic structural health monitoring method may find a broad range of applications in space industry, particularly in pre-launch qualification and diagnosis and re-certification for a next flight.
Keywords Acousto-elastic
Artificial satellites
Bolted joints
Embedded ultrasonics
Piezoelectric sensors
Structural health monitoring

Source Agency Non Paid ADAS
NTIS Subject Category 41F - Joining
63A - Acoustic Detection
46A - Acoustics
46E - Structural Mechanics
84G - Unmanned Spacecraft
Corporate Author New Mexico Inst. of Mining and Technology, Socorro.
Document Type Technical report
Title Note Final rept. 3 Feb 2009-23 May 2012.
NTIS Issue Number 1307
Contract Number FA9453-09-1-0318

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