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Operational Modal Parameter Estimation from Short Time-Data Series

Arora, Rahul

Abstract Details

2014, MS, University of Cincinnati, Engineering and Applied Science: Mechanical Engineering.
Operational Modal Analysis (OMA) is a technique of extracting modal parameters of a system from output responses only. It is an emerging field in structural dynamics and has been applied to complex structures that are often difficult to analyze using traditional Experimental Modal Analysis (EMA) techniques. Since the input information is unavailable in OMA, the technique makes use of certain assumptions about the input excitation to the system and the data processing methods used by current OMA algorithms are based on these assumptions. However, in some real-world scenarios not only the forcing function to the system violates these assumptions but also the time data series of system response is short in length and buried under noise. In such cases, ensemble averaging techniques for filtering out noise are rendered ineffective and the current OMA algorithms which utilize power spectrum and correlation functions result in inconsistent modal parameters, especially modal damping. This research develops a time domain operational modal parameter estimation (MPE) method based on describing the total system response as a Nonlinear Auto Regressive process with eXogenous input (NARX) wherein the linear part of the model describes the response of the structure and the nonlinear terms fit the noise present in data series. The method is developed in line with the concept of Unified Matrix Polynomial Approach (UMPA) and utilizes a set of least squares solutions to compute modal parameters.
Randall Allemang, Ph.D. (Committee Chair)
David L. Brown, Ph.D. (Committee Member)
Allyn Phillips, Ph.D. (Committee Member)
1 p.

Recommended Citations

Citations

  • Arora, R. (2014). Operational Modal Parameter Estimation from Short Time-Data Series [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397467142

    APA Style (7th edition)

  • Arora, Rahul. Operational Modal Parameter Estimation from Short Time-Data Series. 2014. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397467142.

    MLA Style (8th edition)

  • Arora, Rahul. "Operational Modal Parameter Estimation from Short Time-Data Series." Master's thesis, University of Cincinnati, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397467142

    Chicago Manual of Style (17th edition)