@Article{sl.2010.003.213,
AUTHOR = {Younho Cho, Weibin Li, Bin Yang},
TITLE = {Evaluation of Thermal-damages in Tube-like Structures using Ultrasonic Guided Waves},
JOURNAL = {Structural Longevity},
VOLUME = {3},
YEAR = {2010},
NUMBER = {3},
PAGES = {213--219},
URL = {http://www.techscience.com/sl/v3n3/42703},
ISSN = {1944-6128},
ABSTRACT = {This paper aims at an experimental method for detecting thermal-damages
in a tube-like structure using acoustic nonlinear parameter of ultrasonic guided
waves. The material nonlinearity of aluminum pipe specimens, which have been
subjected to different heat-loading cycles, is measured to characterize the microdamages. Flexible Polyvinylidene Fluoride (PVDF) comb transducers are used to
generate and receive the fundamental and second harmonic waves. The amplitude
of the second harmonic wave is extracted from the Fast Fourier Transform (FFT)
spectrum of a received signal. The measured relative nonlinear parameter increases
monotonically as a function of the propagation distance, and the relative nonlinear
parameter becomes greater when the specimen is exposed to higher heat-loading
cycles. These results indicate that the proposed experimental setup is applicable to
assessment the micro-damages in a pipe, and the relative nonlinear parameter is a
potential candidate for the prediction of micro-damages in a tube-like structure.},
DOI = {10.3970/sl.2010.003.213}
}