Ultrasonic thickness structural health monitoring of steel pipe for internal corrosion

dc.contributor.advisor Leonard J. Bond
dc.contributor.author Eason, Thomas
dc.contributor.department Aerospace Engineering
dc.date 2018-08-11T15:22:29.000
dc.date.accessioned 2020-06-30T03:04:29Z
dc.date.available 2020-06-30T03:04:29Z
dc.date.copyright Sun Jan 01 00:00:00 UTC 2017
dc.date.embargo 2001-01-01
dc.date.issued 2017-01-01
dc.description.abstract <p>The naphthenic acid corrosion that can occur in oil refinery process plants at high temperature (400à  à °C) due to the corrosive nature of certain crude oils during the refining process can be difficult to predict. Therefore, the development of online ultrasonic thickness (UT) structural health monitoring (SHM) technology for high temperature internal pitting corrosion of steel pipe is of interest. A sensor produced by the sol-gel ceramic fabrication process has the potential to be deployed to monitor such pitting corrosion, and to help investigate the mechanisms causing such corrosion. This thick-film transducer is first characterized using an electric circuit model. The propagating elastic waves generated by the transducer are then experimentally characterized using the dynamic photoelastic visualization method and images of the wave-field are compared with semi-analytical modeling results. Next, the classic elastic wave scattering theory for an embedded spherical cavity is reviewed, results are compared with a newer scattering theory from the seismology community, that has been applied to a hemispherical pit geometry. This hemispherical pit theory is extended so as to describe ultrasonic Non-Destructive Evaluation (NDE) applications, for pitting corrosion, with the derivation of a far-field scattering amplitude term. Data from this new scattering theory is compared with experimental results by applying principals from the Thompson-Gray measurement model. The initial model validation provides the basis for a possible new hemispherical pit geometric reference standard for ultrasonic NDE corrosion applications. Next, UT SHM measurement accuracy, precision, and reliability are described with a new weighted censored relative likelihood methodology to consider the propagation of asymmetric uncertainty in quantifying thickness measurement error. This new statistical method is experimentally demonstrated and applied to thickness measurement data obtained in pulse-echo and pitch-catch configurations for various time-of-flight thickness calculation methods. Finally, the plastic behavior of a corroded steel pipe is modeled with analytical and finite element methods to generate prognosis information.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/15513/
dc.identifier.articleid 6520
dc.identifier.contextkey 11055505
dc.identifier.doi https://doi.org/10.31274/etd-180810-5130
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/15513
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/29696
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/15513/Eason_iastate_0097E_16310.pdf|||Fri Jan 14 20:42:21 UTC 2022
dc.subject.disciplines Mechanical Engineering
dc.subject.disciplines Statistics and Probability
dc.subject.keywords measurement uncertainty
dc.subject.keywords phototelastic visualization
dc.subject.keywords pitting corrosion
dc.subject.keywords scattering amplitude
dc.subject.keywords sol-gel
dc.subject.keywords ultrasonic thickness
dc.title Ultrasonic thickness structural health monitoring of steel pipe for internal corrosion
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 047b23ca-7bd7-4194-b084-c4181d33d95d
thesis.degree.discipline Engineering Mechanics
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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