| Title |
Modal Parameter Estimation of a Heavy Damped Structure Using the State-Space Modal Responses |
| DOI |
https://doi.org/10.5659/JAIK.2021.37.8.197 |
| Keywords |
Vibration control system; Heavy damped structure; Non-classical damping; State space based mode decomposition; Modal parameter estimation |
| Abstract |
The diverse vibration control systems have been applied to many structures for the enhancement of the earthquake or wind resistant
performance. Since such a heavy damped structure has nonclassical damping natures, it is faced some difficulties in extracting modal response
in the monochromatic form and in estimating the modal properties precisely with conventional mode decomposition method developed in
physical coordinate. In this study, a state-space based modal decomposition technique is proposed to extract modal response from measured
response of a heavy damped structure, and to identify the modal properties using the decomposed modal response in the state space. It is
analyzed the characteristics of power spectrum of the decomposed modal response, and then a process to identify the modal properties,
particularly the damping ratio is addressed. For the verification of the proposed method, the technique is applied to the 3DOF system with
the oil dampers and the structure with a tuned mass damper system. From the simulation results, it is found that the transfer function of the
modal response in the state space is composed of a combination the displacement and velocity transfer function, and so more precise modal
parameter estimation can be expected when the participation ratio of two components is appropriately addressed. |