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Project
Identification of Systems excited by Arbitrary unknown Inputs using output-only measurements (FWOAL627)
The application of system identification to vibrating structures resulted some 30 years ago in a new research discipline in mechanical engineering known as "Experimental Modal Analysis" (EMA).
EMA identification methods and procedures are limited to forced excitation laboratory tests where the applied forces can be measured together with the response of the structure (e.g., accelerations). Today, modal analysis has become a widespread means of finding the modes of vibration of a machine or structure. In many applications, however, the vibration measurements have to be performed in "operational" conditions where the structure is excited by the natural (ambient) excitation sources. During a flight flutter test for instance the airplane's wings are excited by air turbulence. In such a case, it is practically impossible to measure the input forces, and consequently, the accelerations (outputs) are the only signals that can be measured. Traditional output-only techniques assume that the outputs are the results of a stochastic process with white noise sources as inputs. The transmissibility-based approach proposed in this project has the key advantage that it can be used with arbitrary inputs (including varying harmonic forces).
EMA identification methods and procedures are limited to forced excitation laboratory tests where the applied forces can be measured together with the response of the structure (e.g., accelerations). Today, modal analysis has become a widespread means of finding the modes of vibration of a machine or structure. In many applications, however, the vibration measurements have to be performed in "operational" conditions where the structure is excited by the natural (ambient) excitation sources. During a flight flutter test for instance the airplane's wings are excited by air turbulence. In such a case, it is practically impossible to measure the input forces, and consequently, the accelerations (outputs) are the only signals that can be measured. Traditional output-only techniques assume that the outputs are the results of a stochastic process with white noise sources as inputs. The transmissibility-based approach proposed in this project has the key advantage that it can be used with arbitrary inputs (including varying harmonic forces).
Date:1 Jan 2012 → 31 Dec 2015
Keywords:mechanica
Disciplines:Other engineering and technology