• Login
    View Item 
    •   SMARTech Home
    • Georgia Tech Theses and Dissertations
    • Georgia Tech Theses and Dissertations
    • View Item
    •   SMARTech Home
    • Georgia Tech Theses and Dissertations
    • Georgia Tech Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Evaluation of simulated plain dents in x52 pipeline steel using nonlinear Rayleigh waves

    Thumbnail
    View/Open
    PFEIFER-THESIS-2019.pdf (12.70Mb)
    Date
    2019-10-04
    Author
    Pfeifer, Denis
    Metadata
    Show full item record
    Abstract
    This research investigates the microstructural damage in X52 pipeline steel caused by a plain dent using nonlinear ultrasound. Therefore, the plastic deformation of a plain dent is simulated by loading X52 steel specimens on a tensile testing machine to different strain levels. A Rayleigh wave with fundamental frequency omega is then excited using a wedge-coupled transducer. As this wave propagates along the specimen's surface a second harmonic wave with frequency 2*omega is generated. The the slope of amplitude ratio A2/A1^2 measured over the propagation distance yields the relative acoustic nonlinearity parameter beta'. The relative acoustic nonlinearity parameter increases with increasing plastic deformation due to the increasing signs of material damage, such as dislocations.Thus, the nonlinear ultrasound measurements are sensitive to microstructural changes caused by plastic deformation in X52 pipeline steel. Comparing the results of round specimens to flat specimens lead to the conclusion that the comparatively high variability in the measurements is not caused by the round geometry of the pipeline but by the inherent variability due to manufacturing processes and localized effects in the material during the plastic deformation.
    URI
    http://hdl.handle.net/1853/62287
    Collections
    • Georgia Tech Theses and Dissertations [23877]
    • School of Civil and Environmental Engineering Theses and Dissertations [1755]

    Browse

    All of SMARTechCommunities & CollectionsDatesAuthorsTitlesSubjectsTypesThis CollectionDatesAuthorsTitlesSubjectsTypes

    My SMARTech

    Login

    Statistics

    View Usage StatisticsView Google Analytics Statistics
    facebook instagram twitter youtube
    • My Account
    • Contact us
    • Directory
    • Campus Map
    • Support/Give
    • Library Accessibility
      • About SMARTech
      • SMARTech Terms of Use
    Georgia Tech Library266 4th Street NW, Atlanta, GA 30332
    404.894.4500
    • Emergency Information
    • Legal and Privacy Information
    • Human Trafficking Notice
    • Accessibility
    • Accountability
    • Accreditation
    • Employment
    © 2020 Georgia Institute of Technology