An interface decomposition technique on reducing the size of conventional Component Mode Synthesis (CMS) models

Component Mode Synthesis methods are well-established and widely used model reduction procedures.Typically each component is modeled using finite element analysis, with the interface being represented by the Degrees Of Freedom (DOFs) of the nodes lying on the interface between the various components. One difficulty, however, is that there may be very many interface DOFs, especially for continuous line or area interfaces between substructures, e.g., between plates or solid components. In this paper, methods for reducing the number of interface DOFs are considered with particular reference to fixed-interface (Craig-Bampton) models. A technique is described in which a set of interface basis functions is selected and the interface nodal DOFs projected onto these new coordinates, which then lead to new forms for the constraint modes. If suitably chosen, relatively few interface basis functions are required for accurate computation, and hence the size of the model can be significantly reduced. Meanwhile, incompatible models, i.e., interface deformations of the two components that are described by different numbers of degrees of freedom, can be easily accommodated within the approach. Numerical examples are presented to illustrate the validity of the present theory. Good performance is observed.