Frf-based Finite Element Model Updating Method for Non-viscous and Non-proportional Damped System

The modeling of damping is very complex and still considered somewhat an unknown or grey area. Recently, model updating methods has been used to update the damping matrix based on measured dynamic test data to accurately represent energy dissipation mechanism in dynamic systems. Most of the finite element updating methods considers that the dynamic systems are viscous and proportional. In this paper, a new finite element model updating method is proposed in which damping is considered as non-viscous and nonproportional. The proposed method is frequency response function (FRF)-based and the updating model reflects general damping in the dynamic system. The effectiveness of the proposed damped finite element updating method is demonstrated by numerical examples and by actual laboratory experiments. The updated results have shown that the proposed damped element model updating method can be used to derive accurate models for nonviscous and non-proportional damped systems. This is illustrated by matching the complex FRFs obtained from the updated model with that from the experimental data.