The Rayleigh-Ritz Method With Quasi-Comparison Functions in Nonself-Adjoint Problems

Abstract

In the determination of the first eigenmodes of continuous linear elastic systems the Rayleigh-Ritz method is often used. It is also very useful in the discretization of the elastic members of multibody systems undergoing large nonlinear motions. Recently the concept of quasi-comparison functions has been introduced for the Rayleigh-Ritz discretization in self-adjoint eigenvalue problems, where it may lead to a considerable improvement of the convergence when compared with other classes of admissible functions. In this paper it is shown with a simple example that a similar phenomenon also holds for nonself-adjoint problems. Since the exact solutions are known, precise information on the errors can be given.