Frequency analysis of the acoustic signal transmitted through a one-dimensional chain of metallic spheres

This work investigates the propagation of acoustic pulses through a chain of elastic spheres embedded in air. This study is an extension of the works realized on individual sphere by several authors for measuring elastic constant and internal friction with a monofrequential acoustic excitation. The frequency analysis of the experimental transmitted train waves exhibit maxima which were correlated to different types of free vibration modes: the Rayleigh modes (R-nl), the torsional modes (T-nl), and the spheroidal modes (S-nl). These resonances may be generated separately according to the polarization of the excitation pulse. (C) 2001 Acoustical Society of America.