Model order reduction of flexible multibody systems described by the ANCF

The absolute nodal coordinate formulation (ANCF) is used to model flexible multibody systems with geometrical nonlinearities of both overall motions and large deformations. However, significant computational cost is required when handling the systems with a great number of degrees of freedom. In order to improve efficiency, the Reduced-Order Models (ROMs) are constructed based on the proper orthogonal decomposition and Galerkin projection methods for multiple simulations of multibody systems. A simple approach for the selection of reduced constraint equations is proposed to deal with the singularity of the coefficient matrices of ROMs. After that, the fast-to-slow ROM method is proposed to make the ROM be adaptive to the change of system parameters. The reduced-order basis vectors extracted from the fast dynamic responses are used to simulate slow dynamic responses. Finally, numerical examples are given to validate the effectiveness and efficiency of the proposed model order reduction scheme for flexible multibody systems.