ИСТИНА

The propagation velocities of longitudinal and shear acoustic waves in the sample with 100% filling with ABS were measured. The metamaterial sample has been designed and made of ABS plastic for this experimental study. It consists of a set of plane parallel gratings the number of which in the sample could vary. Each grating in the sample consisted of 16 parallel 1.02 mm wide by 45 mm length square rods with a period of 2.51 mm. The amplitude-frequency characteristics (AFC) of the fabricated metamaterial sample placed in the air were measured in the frequency range (35-100) kHz using longitudinal acoustic waves. At the AFC of the sample, a band gap (stop band) was detected and investigated. It was discovered that the increase in the number of grating layers in the sample led to an increase in the attenuation coefficient of acoustic wave at the band gap and to a narrowing of the band gap. The central frequency of the band gap remained the same. A numerical simulation of the frequency response of the sample was carried out. The results of experimental studies and numerical simulations are in satisfactory agreement. The diffraction pattern of ultrasound scattering of the sample was investigated. The obtained results can be used in solid-state physics, materials science, to create materials with controlled frequency-dependent acoustic properties.