Tunable phononic crystals based on cylindrical Hertzian contact

We investigate the tunability of phononic crystals consisting of arrays of cylindrical elements using theoretical, numerical, and experimental approaches. We show that when these systems are excited by a continuous dynamic signal under large static precompression, they support a characteristic band structure whose cutoff frequency can be controlled by changing the alignment angles or the static precompression. Furthermore, we report the formation of an additional pass band when there exists particles eccentricity, which is caused by the coupling mechanism between longitudinal and shear modes.