| Title |
Modal Parameter Identification of Structures based on Vibration Test |
| Authors |
Kim Hong-Jin ; Hwang Jae-Seung ; Cho Bong-Ho ; Jo Ji-Seong |
| Keywords |
Modal Participation Factor ; Mode Shape ; System Identifiation |
| Abstract |
The load distribution to each mode of a structure under seismic loading depends on the modal participation factor and thus the exact estimation of the modal participation factor is essential to analyze the seismic response of a structure. The modal participation factor of an idealized analytical model, however, is different to the actual one due to modeling and construction error. Therefore, there exist limits on the estimation of actual behavior. In this study, an identification procedure for participation factor based on vibration test is proposed. The modal participation factor is obtained from the relationship between observability matrices realized from system identification. Using the oberservability matrices, it is possible to transform an arbitrarily identified state space model from the experimental data into a typical state space model which is defined in a domain with physical meaning. Then, the modal participation factor can be estimated based on the relationship between two state space models related by the oberservability matrices. The proposed procedure has an advantage that the modal participation factor for the mode shape vector can be estimated from the response of the corresponding floor without knowing responses of other floors. Further, the mode shape vector can also be estimated directly from the experimentally estimated modal participation factors. The numerical simulation and experimental verification are performed to evaluate the proposed procedure. The results show that the modal participation factor and mode shape vectors are estimated from the structural responses precisely. |