Dispersion behavior of guided waves in hollow cylinders (cylindrical waves)
was evaluated theoretically and experimentally, Observed dispersion behavi
or suggests an assignment, different from the traditional one, of longitudi
nal (L-), flexural (F-) and torsional (T-) modes which are consistent with
Lamb waves and shear-horizontal (SH) mode waves. The L- and F-modes of the
cylindrical waves have characteristics which are asymptotic to Lamb waves a
nd to waves in a solid cylinder. Experimentally, wide-band cylindrical wave
s in aluminum pipes were generated using a laser-ultrasonic method. Wavelet
transform of, the cylindrical wave signals was utilized for time-frequency
analysis in order to compare the ln with the theoretical dispersion curves
. For the L(0, 1), F(1, 1), F(2, 1), L(0, 2), F(2, 2) and F(2, 2) modes of
the cylindrical waves, which were efficiently excited, theoretical and expe
rimental dispersion curves agree with each other.