PROPAGATION CHARACTERISTICS OF ELASTIC CIRCUMFERENTIAL WAVES IN NUCLEAR-FUEL CLADDING TUBES

The backscattering of a plane acoustic wave from an air-filled Zircaloy-4 nuclear fuel cladding tube in water is analysed as a function of k1a using the resonance scattering theory. In accordance with the cut-off frequencies, the groups of resonances are identified as the elastic circumferential waves corresponding to the Lamb plate waves. In order to determine accurate propagation characteristics, each resonance is evaluated using the very small calculation step, DELTA(k1a) = 0.0001, and the results are presented in the form of phase and group velocities, attenuation constants and angles, and backscattered amplitudes of the elastic circumferential waves as function of the frequency, tube thickness and curvature.