APPLICATION OF ERA'S METHOD FOR THE EXPERIMENTAL MODAL ANALYSIS OF COMPOSITE STRUCTURES
DOI:
https://doi.org/10.26512/ripe.v2i15.21386Keywords:
ERA. Composite structures. Modal analysis. Identification of global properties.Abstract
This work is placed on the scope of characterization and modeling of structures and the central objective is to establish a computer code capable to provide models for structures of interest from practical experimentation, to be used to refine the computer models a posteriori. To realize that project, the experimental modal analysis was applied in the Eigensystem Realization Algorithm ”“ ERA. As well as most of the techniques of identification of dynamic of systems, the ERA also creates the compute modes, being necessary the application of procedures for filtering the real modes before the noises and/or computers modes. In this work, two techniques for the distinction were used: Modal Amplitude Coherence (MAC) and Modal Singular Value (MSV). Beside this, a novel approach to help interpret and filter based in MSV deviation was proposed and tested, producing good results. To achieve this, a computer code that receives experimental data and returns the global properties of the system, i.e., the natural frequencies, the damping factors and the mode shapes was developed. The preliminary results, developed in the know structure, indicate the code has the potential to handle with complex geometries.
Downloads
References
Alves, M. T. S., 2005. Avaliação numérico experimental de métodos ERA/OKID para identificação de sistemas mecânicos, Tese de mestrado, Universidade Federal de Uberlândia. Alvin, K. F., Robertson, A. N., Reich, G. W., & Park, K. C., 2003. Structural system identification: from reality to models. Computers & structures, 81(12), 1149-1176.
Bayard, D.S., 1992. An algorithm for state-space frequency domain identification without windowing distortions, Proceedings of the 31st Conference on Decision and Control, v.2, p.1707-1712. Chiang, D. Y., & Lin, C. S., 2010. Identification of modal parameters from ambient vibration data using eigensystem realization algorithm with correlation technique. Journal of Mechanical Science and Technology, 24(12), p. 2377-2382.
Ho, B. L. and Kalman, R. E., 1965. Effective construction of linear state-variable models from input/output data, Proceedings of the 3rd Annual Allerton Conference on Circuit and System Theory, IL University of Illinois, p. 449-459. Juang, J. N., & Pappa, R. S., 1985. An eigensystem realization algorithm for modal parameter identification and model reduction. Journal of guidance, control, and dynamics, 8(5), p. 620-627.
Kung, S. Y., 1978. A new identification and model reduction algorithm via singular value decomposition. 12th Asilomar Conference on Circuits, Systems and Computers, p 705-714.
Lawton, T, 2015. The aerospace report. Institute of Mechanical Engineering, London, July 2015.
Mouritz, A. P., Bannister, M. K., Falzon, P. J., Leong, K. H., 1999, Review of applications for advanced three-dimensional fibre textile composites. Composites: Part A 30 (1999) 1445-1461. Phan, M., Horta, L. G., Juang, J. N., & Longman, R. W., 1993. Linear system identification via an asymptotically stable observer. Journal of Optimization Theory and Applications, 79(1), 59-86.
Sczibor, V., 2002. Identificação modal de uma estrutura Aeronáutica via algoritmo de realização de sistemas, Tese de mestrado, Escola de Engenharia de São Carlos. Zeiger, P., & McEwan, J., 1973. Approximate Linear Realizations of Given Dimension Via Ho's Algorithm; CU-CS-012-73.
Downloads
Published
How to Cite
Issue
Section
License
Given the public access policy of the journal, the use of the published texts is free, with the obligation of recognizing the original authorship and the first publication in this journal. The authors of the published contributions are entirely and exclusively responsible for their contents.
1. The authors authorize the publication of the article in this journal.
2. The authors guarantee that the contribution is original, and take full responsibility for its content in case of impugnation by third parties.
3. The authors guarantee that the contribution is not under evaluation in another journal.
4. The authors keep the copyright and convey to the journal the right of first publication, the work being licensed under a Creative Commons Attribution License-BY.
5. The authors are allowed and stimulated to publicize and distribute their work on-line after the publication in the journal.
6. The authors of the approved works authorize the journal to distribute their content, after publication, for reproduction in content indexes, virtual libraries and similars.
7. The editors reserve the right to make adjustments to the text and to adequate the article to the editorial rules of the journal.
