Article ID: 24-00394
In this study, we present a method for determining parameters that are essential for evaluating the health of layered structures. This method uses modal parameters to identify characteristic parameters that can accurately reproduce the measured modal damping ratio. Specifically, the proposed method uses natural frequencies, natural vibration modes, and modal damping ratios identified via an experimental modal analysis to identify characteristic parameters of stiffness and damping matrices whose characteristic matrix shapes are assumed in advance. This study aims to obtain a good representation of the damping characteristics of the system of interest and a good match between the reconstructed and original frequency response functions (FRFs). In the field of architecture, mass is often considered to be known. Hence, this study treats the mass matrix as known. This study takes a three-layer structure as an example, proposes an identification method, and verifies the validity and applicability of the proposed method via numerical simulations and experiments. The results show that it is necessary to adopt a damping model that can reproduce the actual modal damping ratios well and that both damping models employed in the numerical simulations can reproduce the modal damping ratios well. Next, the applicability of the proposed method is verified using experimental data. In practice, it is difficult to completely reproduce measured modal damping ratios. However, the results of this study show that damping characteristics that closely reproduce the measured modal damping ratios can be obtained.
