Advisor(s)
Dionisio Bernal
Date of Award
8-2010
Date Accepted
8-2010
Degree Grantor
Northeastern University
Degree Level
M.S.
Degree Name
Master of Science
Department or Academic Unit
College of Engineering. Department of Civil and Environmental Engineering.
Keywords
civil engineering, mode normalization, mass perturbation, plates
Subject Categories
Modal analysis, Plates (Engineering)
Disciplines
Civil and Environmental Engineering
Abstract
In modal identification, there are often practical applications where input forces cannot be determined, and output-only analysis must be implemented. A limitation of output-only identification is that the scaling which connects eigenvectors to the input-output response of the system is unknown. One particular strategy to obtain this normalization involves introducing a known perturbation to the system in question - typically a change in mass. Existing techniques operate under the assumption that the eigenvectors of the system are real, meaning that the system is undamped or classically damped. Although this often provides a reasonable approximation, it is never strictly true. In this thesis, an approach is outlined which calculates the required scaling factors without the assumption of classical damping. Specifically, the method solves for the scaling factors from an over-determined system of equations generated by evaluating the pole residue form of the Receptance matrix at the poles of the perturbed system. This new approach was verified through an experimental program on an aluminum plate, and the results compared favorably to those of other mode normalization techniques.
Document Type
Master's Thesis
Rights Holder
Matthew Maddalo
Permanent URL
Recommended Citation
Maddalo, Matthew, "An experimental examination of mass perturbation strategies to mode normalization in a plate" (2010). Civil Engineering Master's Theses. Paper 18. http://hdl.handle.net/2047/d20002087
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