Modal Parameter Uncertainty Estimates as a Tool for Automated Operational Modal Analysis: Applications to a Smart Building
The knowledge of modal parameter uncertainties derived from operational modal analysis (OMA) can greatly improve automated decisions by providing information about the quality of the modal identification. Yet so far, this information has been largely ignored in continuous monitoring studies on civil infrastructure, especially with respect to buildings. In this paper, we implement an automated version of Covariance Based Stochastic Subspace Identification on a highly instrumented smart building. An expansion of the technique estimates uncertainty bounds for all modal parameters. Through a series of full scale experiments, we demonstrate how uncertainties are valuable tools in various contexts of automation. These include the identification and removal of badly-fitted modes, the identification of periods of high signal-to-noise ratio, and the validation of reference sensors selection.
KeywordsModal analysis Buildings Instrumentation Uncertainty Automation
The authors acknowledge the support as well as the collaborative efforts provided by our sponsors, VTI Instruments, PCB Piezotronics, Inc.; Dytran Instruments, Inc.; and Oregano Systems. The authors are particularly appreciative for the support provided by the College of Engineering at Virginia Tech through Dean Richard Benson and Associate Dean Ed Nelson as well as VT Capital Project Manager, Todd Shelton, and VT University Building Official, William Hinson. The authors would also like to acknowledge Gilbane, Inc. and in particular, David Childress and Eric Hotek. We are especially thankful to the Student Engineering Council (SEC) at Virginia Tech and their financial commitment to this project. Dr. Tarazaga is also thankful for the support provided by the John R. Jones III Fellowship. The work was conducted under the patronage of the Virginia Tech Smart Infrastructure Laboratory and its members.
- 1.Brincker, R., Andersen, P., Jacobsen, N.-J.: Automated frequency domain decomposition for operational modal analysis. In: Proceedings of the 13th SEM International Modal Analysis Conference, Nashville, pp. 661–667 (1995)Google Scholar
- 11.Döhler, M., Mevel, L., Andersen, P.: Efficient uncertainty computation for modal parameters in stochastic subspace identification. In: Proceedings of the International Cnference on Uncertainty in Structural Dynamics, pp. 4793–4805 (2012)Google Scholar
- 15.Sarlo, R., Tarazaga, P., Kasarda, M.: Operational modal analysis of a steel-frame, low-rise building with L-shaped construction. In: Proceedings of SPIE – The International Society for Optical Engineering, vol. 10168 (2017)Google Scholar