摘要：For computer-aided analytic research of complexvibrating systems with a large finite number of degrees offreedom, including linear stationary systems, variousmethods, for example, the method of finite elements and soon, are applied [1-5].In the Paper, the mentioned linear vibrating sys-tems are discussed upon. They are described by linear dif-ferential equations with constant coefficients. For digitalintegration of such equations, Runge-Kutta and othermethods are applied. In a majority of cases, such systemshave a very wide spectrum of natural frequencies; how-ever, an investigator takes an interest in the much narrowerrange of the lowest natural frequencies within the saidspectrum only. The high natural frequencies considerablyincrease the time of digital integration, so it is important tohave a system of differential equations for describing theobject under investigation where such frequencies are ab-sent in the roots of its characteristic equations. Such equa-tions can be obtained by reducing the number of degrees offreedom in the dynamical model of object under investiga-tion. However, in many case, this task is difficult or evenimpossible. For example, such a problem appears when themethod of finite elements is applied.
