Approximate eigensolution of locally modified regular structures using a substructuring technique

A structure is called regular if its model can be considered as a product graph. A great computational advantage of regular structures, especially in the context of free vibration analysis, is their capacity for decomposition. In the present paper, the idea of decomposition is extended to the analysis of practical structural systems emerging as slight perturbations of the regular ones. A free interface dynamic substructuring method is employed to reformulate the eigenproblem as an assemblage of a base model and the modification part. The proposed method is very efficient in estimating a few lower eigenpairs of large-scale modified regular structures.