Identification of Modal Parameters of Systems with Modal Interference by Ibrahim Time Domain Method
| Autor: | Yu-JheLin, 林宇哲 |
|---|---|
| Rok vydání: | 2016 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 Modal interferences often cause problems on identifiability and affect the accuracy of system identification during the process of modal parameter identification. Major causes of modal interferences include close frequencies, high damping ratios, non-proportional damping…etc. This thesis will investigate modal-parameter identification in time domain, by proposes a method of using the technique of channel-expansion in Ibrahim time domain method to improve identification accuracy.In general, selecting the order of system before using Ibrahim time domain method is important. This thesis proposes Singular Value Decomposition instead of the Method of Least Squares to solve the matrix of system and at the same time evaluate the order of system to avoid the phenomenon of omitted modes. In addition, this thesis proposes the use of the phase angle diagram of frequency response function in conjunction with the amplitude diagram. So that it is easier to distinguish the modes which are influenced by modal interference. SUMMARY Modal interferences often cause problems on identifiability and affect the accuracy of system identification during the process of modal parameter identification. Major causes of modal interferences include close frequencies, high damping ratios, non-proportional damping…etc. This thesis will investigate modal-parameter identification in time domain, by proposes a method of using the technique of channel-expansion in Ibrahim time domain method to improve identification accuracy. In general, selecting the order of system before using Ibrahim time domain method is important. This thesis proposes Singular Value Decomposition instead of the Method of Least Squares to solve the matrix of system and at the same time evaluate the order of system to avoid the phenomenon of omitted modes. In addition, this thesis proposes the use of the phase angle diagram of frequency response function in conjunction with the amplitude diagram. So that it is easier to distinguish the modes which are influenced by modal interference. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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