title: Measurement of cylindrical Rayleigh surface waves using line-focused PVDF transducers and defocusing measurement method.
abstract: Line-focused PVDF transducers and defocusing measurement method are applied in this work to determine the dispersion curve of the Rayleigh-like surface waves propagating along the circumferential direction of a solid cylinder. Conventional waveform processing method has been modified to cope with the non-linear relationship between phase angle of wave interference and defocusing distance induced by a cylindrically curved surface. A cross correlation method is proposed to accurately extract the cylindrical Rayleigh wave velocity from measured data. Experiments have been carried out on one stainless steel and one glass cylinders. The experimentally obtained dispersion curves are in very good agreement with their theoretical counterparts. Variation of cylindrical Rayleigh wave velocity due to the cylindrical curvature is quantitatively verified using this new method. Other potential applications of this measurement method for cylindrical samples will be addressed.
authors.affiliation: Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chun-I
authors.initials: CI
authors.lastname: Lin
authors.affiliation: Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan. Electronic address: yunglee@mil.ncku.edu.tw.
authors.forename: Yung-Chun
authors.initials: YC
authors.lastname: Lee
keywords: Cylindrical surface; Defocusing measurement; Dispersion curve; Line-focused PVDF transducer; Rayleigh surface wave