EXTRACTION OF STRUCTURAL SYSTEM MATRICES FROM AN IDENTIFIED STATE-SPACE SYSTEM USING THE COMBINED MEASUREMENTS OF DVA
✍ Scribed by W.J. KO; C.F. HUNG
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 352 KB
- Volume
- 249
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
A time domain method for the extraction of the structural system matrices (mass, damping and sti!ness matrices) from an identi"ed state-space system is proposed in this paper using the combined measurements of displacement, velocity and acceleration (DVA) together with the input excitations. The method is based on the invariance of continuous-time Markov parameters. An explicit expression of the relationship between the continuous-time Markov parameters, the structural system matrices, and the in#uence matrices for output DVA as well as the input force has been derived. The determination of structural system matrices is also valid when only the displacement, velocity or acceleration responses are measured. In this paper, the equivalent state system matrices are obtained by an algorithm, which combines the eigensystem realization algorithm (ERA) and the autoregressive with exogeneous (ARX) model. The ARX model provides the necessary discrete-time Markov parameters from the measured input and output data, and then the equivalent state system matrices are identi"ed from discrete-time Markov parameters by using the ERA. A lumped mass model with three degrees of freedom is employed to illustrate the accuracy and feasibility of the presented method.
2002 Academic Press