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Title: On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers

Abstract

Integrity monitoring and flaw diagnostics of flat beams and tubular structures was investigated in this research task using guided acoustic signals. A piezo-sensor suite was deployed to activate and collect Lamb wave signals that propagate along metallic specimens. The dispersion curves of Lamb waves along plate and tubular structures are generated through numerical analysis. Several advanced techniques were explored to extract representative features from acoustic time series. Among them, the Hilbert-Huang transform (HHT) is a recently developed technique for the analysis of non-linear and transient signals. A moving window method was introduced to generate the local peak characters from acoustic time series, and a zooming window technique was developed to localize the structural flaws. The time-frequency analysis and pattern recognition techniques were combined for classifying structural defects in brass tubes. Several types of flaws in brass tubes were tested, both in the air and in water. The techniques also proved to be effective under background/process noise. A detailed theoretical analysis of Lamb wave propagation was performed and simulations were carried out using the finite element software system ABAQUS. This analytical study confirmed the behavior of the acoustic signals acquired from the experimental studies. The report presents the background the analysismore » of acoustic signals acquired from piezo-electric transducers for structural defect monitoring. A comparison of the use of time-frequency techniques, including the Hilbert-Huang transform, is presented. The report presents the theoretical study of Lamb wave propagation in flat beams and tubular structures, and the need for mode separation in order to effectively perform defect diagnosis. The results of an extensive experimental study of detection, location, and isolation of structural defects in flat aluminum beams and brass tubes are presented. The results of this research show the feasibility of on-line monitoring of small structural flaws by the use of transient and nonlinear acoustic signal analysis, and its implementation by the proper design of a piezo-electric transducer suite.« less

Authors:
;
Publication Date:
Research Org.:
University of Tennessee, Knoxville (US)
Sponsoring Org.:
USDOE Office of Nuclear Energy, Science and Technology (NE) (US)
OSTI Identifier:
832721
Report Number(s):
DE-FG07-01ID14114/UTNE-08
TRN: US0406686
DOE Contract Number:  
FG07-01ID14114
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 27 Sep 2004
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 22 GENERAL STUDIES OF NUCLEAR REACTORS; ACOUSTICS; ALUMINIUM; BRASS; DEFECTS; DETECTION; DIAGNOSIS; HEAT EXCHANGERS; IMPLEMENTATION; MONITORING; NUMERICAL ANALYSIS; PATTERN RECOGNITION; STEAM GENERATORS; TRANSDUCERS; TRANSIENTS; WATER; WAVE PROPAGATION; STEAM GENERATOR; HEAT EXCHANGER; MONITORING AND DIAGNOSIS; DATA-BASED MODELING; HYBRID MODELING; GROUP METHOD OF DATA HANDLING; HEAT EXCHAGER FOULING; ACOUSTIC SIGNAL ANALYSIS; FAULT DETECTION, ISOLATION, AND LOCATION; HILBERT-HUANG TRANSFORM.

Citation Formats

Belle R. Upadhyaya, and J. Wesley Hines. On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers. United States: N. p., 2004. Web. doi:10.2172/832721.
Belle R. Upadhyaya, & J. Wesley Hines. On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers. United States. doi:10.2172/832721.
Belle R. Upadhyaya, and J. Wesley Hines. Mon . "On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers". United States. doi:10.2172/832721. https://www.osti.gov/servlets/purl/832721.
@article{osti_832721,
title = {On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers},
author = {Belle R. Upadhyaya and J. Wesley Hines},
abstractNote = {Integrity monitoring and flaw diagnostics of flat beams and tubular structures was investigated in this research task using guided acoustic signals. A piezo-sensor suite was deployed to activate and collect Lamb wave signals that propagate along metallic specimens. The dispersion curves of Lamb waves along plate and tubular structures are generated through numerical analysis. Several advanced techniques were explored to extract representative features from acoustic time series. Among them, the Hilbert-Huang transform (HHT) is a recently developed technique for the analysis of non-linear and transient signals. A moving window method was introduced to generate the local peak characters from acoustic time series, and a zooming window technique was developed to localize the structural flaws. The time-frequency analysis and pattern recognition techniques were combined for classifying structural defects in brass tubes. Several types of flaws in brass tubes were tested, both in the air and in water. The techniques also proved to be effective under background/process noise. A detailed theoretical analysis of Lamb wave propagation was performed and simulations were carried out using the finite element software system ABAQUS. This analytical study confirmed the behavior of the acoustic signals acquired from the experimental studies. The report presents the background the analysis of acoustic signals acquired from piezo-electric transducers for structural defect monitoring. A comparison of the use of time-frequency techniques, including the Hilbert-Huang transform, is presented. The report presents the theoretical study of Lamb wave propagation in flat beams and tubular structures, and the need for mode separation in order to effectively perform defect diagnosis. The results of an extensive experimental study of detection, location, and isolation of structural defects in flat aluminum beams and brass tubes are presented. The results of this research show the feasibility of on-line monitoring of small structural flaws by the use of transient and nonlinear acoustic signal analysis, and its implementation by the proper design of a piezo-electric transducer suite.},
doi = {10.2172/832721},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {9}
}