Improving the accuracy of the dual Craig-Bampton method

The objective of the work reported in this paper is to improve the well-known dual Craig-Bampton (DCB) method. The original transformation matrix of the DCB method is enhanced by considering the higher-order effect of residual substructural modes through residual flexibility. Using the new transformation matrix, original finite element models can be more accurately approximated in the reduced models. Herein, additional generalized coordinates are newly defined for considering the 2nd order residual flexibility. Additional coordinates related to the interface boundary can be eliminated by applying the concept of SEREP (the system equivalent reduction expansion process). The formulation of the improved DCB method is presented in detail, and its accuracy is investigated through numerical examples.