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 o f elastic spheres embedded in air. This study is an extension of the works realized on individual sphere by several authors for measuring elastic cons tant and internal friction with a monofrequential acoustic excitation. The frequency analysis of the experimental transmitted train waves exhibit maxi ma which were correlated to different types of free vibration modes: the Ra yleigh modes (R-nl), the torsional modes (T-nl), and the spheroidal modes ( S-nl). These resonances may be generated separately according to the polari zation of the excitation pulse. (C) 2001 Acoustical Society of America.