Development of a High-Performance Method of Vibration Analysis for a Large-Scale Nonlinear System

(A Rational Elimination Method of Higher-Order modes)

Abstract

A rational method of dimensional reduction is developed in order to analyze accurately a nonlinear vibration of a large-scale system with nonlinearity. Almost nodes without strongly nonlinear excitation are transformed into the modal coordinates by using the complex constrained modes that is obtained by fixing the nonlinear nodes. And a small number of modes whose effect on computation accuracy of the vibration analysis is significant are extracted. On the other hand, the remaining modes are appropriately approximated and are eliminated. The low-dimensional model is constructed by these procedures. Furthermore, by applying an efficient method to eliminate higher-order modes, the low-dimensional model is constructed without computation of higher-order eigen pairs. Effectiveness of this method is verified by computational result