Improved substructuring method for eigensolutions of large-scale structures

The substructuring technology possesses much merit when it is utilized in model updating or damage identification of large-scale structures. However, the conventional substructuring technologies require the complete eigensolutions of all substructures available to obtain the eigensolutions of the global structure, even if only a few eigensolutions of the global structure are needed. This paper proposes a modal truncation approximation in substructuring method, in which only the lowest eigensolutions of the substructures need to be calculated. Consequently, the computation efficiency is improved. The discarded higher eigensolutions are compensated by the residual flexibility. The division of substructures and the selection of master modes in each substructure are also studied. The proposed substructuring method is illustrated by a frame structure and a practical bridge. The two case studies verify that the proposed method can improve the original substructuring method significantly.