Evaluation of the Interface Reductions for Craig Bampton Substructured Models.

The Craig Bampton method represents the interior of each subcomponent in a substructured system with a truncated set of normal modes, but retains all of the physical degrees of freedom at the substructure interfaces. This makes it simple to assemble the substructures into a reduced order system model, but means that the reduced order assembly will have as many interface degrees of freedom as the full model. When
the full model mesh is highly refined, this can lead to unacceptably large equations of motion, so interface reduction can be further performed. An established technique for performing interface reduction is based on a secondary eigenvalue analysis of the interface partitions of the assembled stiffness and mass matrices, which corresponds to more natural physical motion at the interface. However, by doing so the advantages of local substructure reduction are lost. More recently, local interface reductions have been developed to
perform the secondary reduction before the substructures are assembled into a system. This poster surveys various interface reduction techniques and compares their performance using a simple finite element model consisting of several interconnected plates. This comparison can be used to determine the suitability of each interface reduction for different problems.