Longitudinal and transverse elastic waves in one-dimensional phononic crystals

We have fabricated one-dimensional phononic crystals making a manual arrangement of alternate layers of aluminum and epoxy. The experimental realization is designed to present longitudinal and transverse phononic band gaps in the range of megahertz frequencies. Detailed studies of mechanical waves transmission have been experimentally performed using the Fourier transform of short duration pulses. The band structure of the phononic crystal is calculated using an analytical formula. There is a good agreement between the experimental results and the theoretical dispersion relation.