Damping estimation via energy-dissipation method

This paper extends an existing single-degree-of-freedom (dof) energy-dissipation scheme to identify damping parameters for multiple-dof vibration systems. The method balances the energy input of the real system against the energy dissipated in a theoretical model to develop the identification algorithms. The theoretical friction model is assumed to consist of the viscous and Coulomb damping components. The proposed algorithms are applicable in the general- and periodic-input cases. According to the numerical studies performed on periodic excitation, the mixed-frequency harmonic input is preferable to the single-frequency one. Moreover, when noise is present in the measurements, increasing the length of integration interval can be a remedy for effects of noise on estimation accuracy. Observations made on numerical study also indicate that estimation results obtained from a band-limited white-noise input are more accurate than those obtained from the periodic one. Such excitations are adopted in the experimental study in which an electrical system is investigated. The experimental results further confirm the validity and reliability of the proposed method. (C) 2007 Elsevier Ltd. All rights reserved.