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Degree

MS, University of Cincinnati, Engineering : Mechanical Engineering, 2010.

Abstract

Conventional Experimental Modal Analysis (EMA) methods have utilized Frequency Response Functions (FRFs) obtained by measuring both output measurements and input forces in a system. In recent years, there has been development of output-only Operational Modal Analysis (OMA) methods that do not require the measurement of input forces under strict assumptions in terms of the nature of excitation forces. These techniques find extensive applications in study of bridges and other structures where the assumptions are satisfied, and where it is difficult to measure input forces. The aim of this thesis work is to explore the use of this methodology for automotive applications. It is important to note that the OMA assumptions might not be necessarily met in this study, and this becomes part of the objective. The real operational condition of a vehicle is at most times very different from its static one. While EMA techniques have been successfully employed on automotive structures to study their modal behavior, it is to be noted that these are not real operating conditions for the automobile. Doing a test on a vehicle in real excitation conditions such as running on a test track also poses several logistical challenges in terms of instrumentation and data acquisition. This thesis work attempts to study automotive structures using output measurements alone, while exciting the structure using means which are closer to real conditions. Results from these tests are compared with well established experimental methods using standard validation tools.

Subject Headings

Mechanical engineering

Keywords

Operational Modal Analysis

Committee / Advisors

Randall Allemang, PhD (Committee Chair)
David Brown, PhD (Committee Member)
Allyn Phillips, PhD (Committee Member)

Pages

68p.

Document number: ucin1277155789
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1277155789

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