Classification into modal clusters based on the modal contribution analysis of a subsystem

This paper addresses a method of classifying modal clusters to realize resonance control. Especially in this paper, this method is applied to the simultaneous placement of resonance frequencies of the multiple modes belonging to a specified modal cluster through a structural modification to a limited subsystem. The method is useful for separating the resonance frequency of the modal cluster to be designed from the peak frequency of the excitation spectrum all at once. Therefore, the paper proposes a method to consider the multiple modes of a whole structure formed from the same mode of the subsystem belonging to the same modal cluster by using the modal contribution analysis method which is proposed by the authors. Then, under the above definition of a modal cluster, we introduce a method of moving the resonance frequencies of multiple modes belonging to the same modal cluster together without significantly changing the resonance frequencies of multiple modes belonging to other modal clusters. Finally, its usefulness is shown by a numerical example.