Modal analysis of a nonlinear periodic structure with cyclic symmetry

This paper carries out modal analysis of a nonlinear periodic structure with cyclic symme-try. The nonlinear normal mode (NNM) theory is brie°y described, and a computationalalgorithm for the NNM computation is presented. The results obtained on a simpli¯edmodel of a bladed assembly show that this system possesses a very complicated struc-ture of NNMs, including similar and nonsimilar NNMs, nonlocalized and localized NNMs,bifurcating and internally resonant NNMs. Modal interactions that occur without neces-sarily having commensurate natural frequencies in the underlying linear system are alsodiscussed.