Experimental Investigation of Slow Relaxation of Sound Velocity in Carbonate Rock

The paper presents the results of comprehensive studies of the phenomenon of slow relaxation of the speed of sound in structurally inhomogeneous materials after vibration exposure to a finite amplitude of deformations. The results were obtained on the experimental setup created for these studies, which ensured high accuracy in measuring the linear and nonlinear acoustic characteristics of various materials. The results of an experimental study of relaxation in a carbonate rock, which is a structurally heterogeneous material with a complex system of internal bonds, are presented. The measurements made it possible to determine the dependences of the relaxation parameters on the amplitude and excitation time, as well as the effects due to the finite amplitude of the probing wave. An interpretation of the obtained results is given and the effects that have not received an exhaustive explanation are noted.