PROPAGATION OF A LOW-FREQUENCY WAVE COMPONENT IN A MODEL OF A BLOCK MEDIUM

摘要

This paper studies the properties of a model of a block m,edium. consisting of absolutely rigid blocks separated by deformable layers. The model is proposed to describe the low-frequency spectral region of a perturbation wave propagating in the medium of this structure. The model is based on the assumption that the low-frequency part of the wave train provides the least distorted information on the average characteristics of the structure of the medium, on the wave pathway. Calculation of waves in a one-dimensional assembly of blocks (rods) and deformable layers show that the model ignoring the deform,ation of the blocks is applicable only in the case where the stiffness of the layer is low compared to the stiffness of the rod. A correction is applied to eliminate this restriction in the case of a long-wave approximation.