Utilization of idealized homogeneous models in the analysis of dynamic processes of impact-actlon machines or in studying wave propagatlon in laminar media and composite material results in rough estimates whose limits of applicability are constrained substantially in the case of rigid effects (and for rigid systems).If problems of nonstationary wave processes in homogeneous elastic media and structures have an ancient history and have been studied ~aell enough (see [i, 2], say), then solutions for structural models are based on numerical methods and have been obtained for specific structures, which does not permit analysis of the general laws inherent to wave processes in systems of similar construction.In the partlchlar case when a real structure can be modeled by a periodic system, an analytic solution has successfully been obtained for the longwave component which is fundamental in the sense of impact energy transfer.The purpose of this paper is to clarify the nature of the change in the initial perturbation during its propagation over composite elastic systems of periodic structure and to estimate the applicability of the results obtained to describe longwave perturbations in systems with spoiled structure.The model of a one-dlmenslonal wavegulde ordinarily used in the analysis of impulse propagation over extended structural elements can be made complicated by imparting to it a structure with characteristic parameters (length, mass, stiffness). The number of such parameters in models of regular configuration can be small, which simplifies the analysis of the mechanical effects.The simplest such model is a rod with stiffly or elastically attached masses [3], a pln-polnt system with local stiffnesses [4], a pin-joint system with transverse connections [5], a cylindrical shell with stringers [6] (this latter model is carried out in the dynamics of structures from the theory of deformation of a unidirectional composite material [7][8][9]). The listed systems combine the fact that the element comprising the period is itself homogeneous but the inhomogeneity (mass, stiffness) is contained at the junctures.Periodic systems containing plecewise-homogeneous elements along both the length and in the transverse direction are considered below. Examples of such systems are represented in Figs. i and 2: a cylindrical shell with stringers and frames (Fig. la), and a laminar medium (Fig. 2a). This latter was used extensively in seismological problems, where mainly the dispersion properties of such systems and the dynamics of composites were investigated. Under a longitudinal impulse action and relatively large radial stiffness of the frames, the radial shell vibrations can be neglected as compared with the longitudinal and the deformation of a doubly periodic plate with a longitudinal-transverse set (Fig. ib) can be considered. The model of a laminar medium with identical acoustic resistances (0,c, : 02c=) corresponds to a rod of plecewlse-homogeneous construction (Fig. 2b).In this paper by using integral transforms with su...