Method for Reduced-Order Modeling with Mode Selection Criterion

A reduced-order modeling (partitioned reduced-order modeling [P-ROM]) method for structural systems is presented, which employs recently developed displacement-only partitioned (DP) equations of motion. It is shown that the DP equations directly yield the same eigenvalues as the assembled equations of finite element model, and the corresponding eigenvectors are a partitioned form of the assembled eigenvectors. A unique feature of the proposed P-ROM method is its a priori mode selection criterion that can be utilized with the desired target accuracy assigned by the modeler. Thus, the proposed P-ROM method bypasses the arduous task of substructural mode synthesis (viz., selecting modes for each substructure) and directly constructs the ROM equations. An attractive feature of the proposed P-ROM method is that it can handle nonmatching mesh problems with ease. The performance of the present P-ROM method is illustrated through several numerical ROM examples and the ensuing transient analysis.