EXPERIMENTAL-OBSERVATION OF WAVE-DISPERSION IN CYLINDRICAL-SHELLS VIA TIME-FREQUENCY ANALYSIS

Dispersion characteristics of longitudinal wave modes in cylindrical shells over a relatively wide frequency range (up to more than 100 kHz) were observed using a very simple and efficient experimental method. The method involves detecting transient waveforms of longitudinal impulse waves (initially transmitted to the shell wall) and performing time-frequency analysis on the detected signals using the short-time Fourier transform (STFT). Two modes of wave propagation were observed, one exhibiting a “low-pass” and the other a “high-pass” type cutoff behavior with a dead zone between them. These results are in agreement with known theories. © 1995, Acoustical Society of America. All rights reserved.