Improvement of Nonlinear Single Resonant Mode Method

Abstract

Presently, the Nonlinear Single Resonant Mode (NLSRM) method is the most efficient method for extending standard linear modal analysis concept to nonlinear systems. In this method, it is assumed that the mode of vibration in the resonant condition is close to the nonlinear normal mode and only one mode has nonlinear behavior. Therefore, predicting which one of the modes will exhibit nonlinear behavior is very important especially for a large system. The main object of this paper is twofold: (1) to improve the NLSRM method, (2) to use the sensitivity analysis for the prediction of nonlinear mode. The results are compared to the results of harmonic balance (HB) and time domain (TD) methods. It is shown that there is a very good agreement between HB and TD results with those of improved NLSRM methods and also the methodology for prediction of nonlinear mode is well suited.