High-Fidelity Flexibility-Based Component Mode Synthesis Method with Interface Degrees of Freedom Reduction

The partitioned structural equations of motion via the method of localized Lagrange multipliers (PALM) consist of internal and interface variables. The model reduction achieved based on PALM is called flexibility-based component mode synthesis (F-CMS), and it thus far has concentrated on reducing the internal degrees of freedom (DOFs) or reducing the internal and interface DOFs at once. In this work, well-defined three-level reduction formulations of the F-CMS method are proposed for better precision: internal DOFs, the localized Lagrange multipliers, and the interface boundary displacement. The proposed formulations include three different reduction techniques for the interface boundary displacement for better computational efficiency. Numerical experiments indicate that the proposed formulations can substantially reduce the overall reduced-order models further without compromising the accuracy, thus achieving a substantial additional reduction of computational cost compared with the previous works. In a...