A COMPARISON OF STRUCTURAL DYNAMIC MODIFICATION AND SENSITIVITY METHOD APPROXIMATION

摘要

Model correlation and damage detection using finite-element physical parameter adjustments have received considerable attention in recent years. When dealing with complex and large-sized models, some form of approximate reanalysis is typically performed. In this work, the performance of structural dynamic modification (SDM) and sensitivity method approximations is assessed with respect to approximation accuracy. For a linear conservative model with no mass perturbation, it will be shown numerically and analytically that SDM produces the same natural frequency estimates as the sensitivity method. In addition, it will be demonstrated that SDM approximations for natural frequencies are superior to that estimated using sensitivity method. However, sensitivity method estimates of mode shapes are superior to the SDM estimates. Finally, an iterative SDM method has been proposed based on the subspace iteration eigensolver algorithm, which drastically improves the mode shape estimates over few iterations.