Abstract
Structures with closely spaced modes can often be hard to correlate with numerical models due to the high sensitivity of the eigenvectors. Even the smallest change in either mass or stiffness can have a large influence on the eigenvectors, and makes it hard to fit a numerical model so its modal parameters matches those obtain from measurements. This paper introduces a robust method for calculating the cross orthogonality check for structures with closely spaced modes. The method utilizes the fact that a cluster of closely spaced eigenvectors from an experiment and from a well correlated numerical model will span the same subspace, although the experimental mode is badly correlated with its corresponding numerical mode. A new basis of numerical modes is created by redefining the closely spaced numerical modes as a linear combination of one another, based on their projection upon the experimental mode. This will enable a more robust calculation of the cross orthogonality check. The method is validated using simulation cases where the errors are evaluated using simulated responses for the different sets of modal parameters.
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© 2015 The Society for Experimental Mechanics, Inc.
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Skafte, A., Aenlle, M.L., Brincker, R. (2015). Cross Orthogonality Check for Structures with Closely Spaced Modes. In: Atamturktur, H., Moaveni, B., Papadimitriou, C., Schoenherr, T. (eds) Model Validation and Uncertainty Quantification, Volume 3. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-319-15224-0_34
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DOI: https://doi.org/10.1007/978-3-319-15224-0_34
Publisher Name: Springer, Cham
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