Substructure Stiffness and Mass Updating through Minimization of Modal Dynamic Residuals

This research studies a substructure finite element model updating approach that requires vibration data from only part of a large structure (i.e., a substructure). The residual structure is condensed using a limited number of dominant modal coordinates, whereas the substructure model remains at high resolution. To update the condensed model, physical parameters in the substructure and modal parameters of the residual structure are chosen as optimization variables; minimization of modal dynamic residuals from the eigenvalue equations in structural dynamics is chosen as the optimization objective. An iterative linearization procedure is adopted for efficiently solving the optimization problem. The proposed substructure model updating approach is validated with 1D, 2D, and 3D examples.