Direct Structural Damping Identification Method

Abstract

All structures exhibit some form of damping, but despite a large literature on the damping, it still remains one of the least well-understood aspects of general vibration analysis. The synthesis of damping in structural systems and machines is extremely important if a model is to be used in predicting vibration levels, transient responses, transmissibility, decay times or other characteristics in design and analysis that are dominated by energy dissipation. In this paper, a new structural damping identification method is proposed. The proposed structural damping identification is a direct method and requires prior knowledge of accurate mass and stiffness matrices. The proposed method doesn’t require initial damping estimates. The effectiveness of the proposed structural damping identification method is demonstrated by numerical and experimental studies. Firstly, a numerical study is performed using lumped mass system. The numerical study is followed by a case involving actual measured data of cantilever beam structure. The results have shown that the proposed structural damping identification method can be used to derive accurate model of the system. This is illustrated by matching of the complex FRFs obtained from the analytically damped model with that of experimental data.