Prediction of Ultrasonic Guided Wave Dispersion in Bent Pipes Using Finite Element Analysis and 2-D Fourier Transform
In this paper, the dispersion curves of a bent cylindrical pipe are obtained by using the 3-dimensional finite element modeling and 2-dimenstional Fourier transform. The transient responses of the bent pipe are calculated by using a general-purpose finite element program, and the displacements are extracted at a series of sequential points as a function of spatial position and time, u(x,t). Then 2-dimentional FFT of u (x,t) offers U (k,ω), the relation between wave number and angular frequency so that the phase velocity and group velocity can be calculated. In addition, verification of the result is made by the mode identification using wavelet transform. The modes invoked by both methods agree very well.
Young-Jin Kim, Dong-Ho Bae and Yun-Jae Kim
S. J. Song et al., "Prediction of Ultrasonic Guided Wave Dispersion in Bent Pipes Using Finite Element Analysis and 2-D Fourier Transform ", Key Engineering Materials, Vols. 297-300, pp. 2065-2070, 2005