
Accession Number : AD0617855
Title : ON THE METHODS OF GALERKIN, RITZ AND KRYLOVBOGOLIUBOV IN THE THEORY OF NONLINEAR VIBRATIONS.
Descriptive Note : Revised ed.,
Corporate Author : IMPERIAL COLL OF SCIENCE AND TECHNOLOGY LONDON (ENGLAND)
Personal Author(s) : Newland,D. E.
Report Date : 05 AUG 1964
Pagination or Media Count : 17
Abstract : The conditions for equivalence of the Galerkin method and the Ritz minimizing method are reviewed. It is then shown that Galerkin's method may also lead to a result which, for steady state vibrations, is the same as the first approximation of KrylovBogoliubov. Both the Ritz method and the first approximation of KrylovBogoliubov may therefore be thought of as special cases of the general Galerkin method. The difference between them lies in the different ways in which the describing differential equations are expressed, in the different forms of the approximate solution used, and in the different choice of Galerkin weighting functions. As an example of these differences, the free vibration of a centrifugal pendulum is considered. This is a two degreesoffreedom problem with a known exact solution. The exact solution is compared with approximate solutions by the Ritz minimizing method and the method of KrylovBogoliubov. It turns out that the two methods give results which are practically indistinguishable from each other, and very close to the exact answer. (Author)
Descriptors : (*VIBRATION, THEORY), (*NUMERICAL METHODS AND PROCEDURES, VIBRATION), PERTURBATION THEORY, DIFFERENTIAL EQUATIONS, MOTION
Distribution Statement : APPROVED FOR PUBLIC RELEASE