A dynamic substructuring-based parametric reduced-order model considering the interpolation of free-interface substructural modes

A parametric reduced-order model (PROM) was developed by using a free-interface coupling method. For dynamic substructuring, the accuracy of the free-interface assembly is generally higher than that of the fixed interface one in a low frequency range, since it considers free-interface normal modes and rigid-body modes of each substructures. Therefore, by using the free-interface coupling method, we can enhance the accuracy of the PROM developed previously, in particular, the one formulated with a primal assembly. One important characteristic to retain the efficiency of PROM in the free-interface assembly is that the interpolation of substructural modes should be discriminated considering the characteristics of the modes. In the present work, we newly suggest a strategy for interpolating free-interface mode according to the change of parameter values. To verify the accuracy of the proposed PROM, we investigated the accuracy of the eigenvalues with a high-dimensional parametric input space.