Quantifying the Correlation Between Measured and Computed Mode Shapes

SD Garvey, JET Penny (Aston University) & MI Friswell (University of Wales Swansea)

Journal of Vibration and Control, Vol. 2, No. 2, May 1996, pp. 123-144


This paper proposes a method whereby a set of computed mode shapes for a structure and set of measured mode shapes may be compared through the mass matrix. The errors between the two are found to fall into three categories: (a) mutual orthogonality of the measured modes is not satisfied, (b) the sets of modal vectors do not span the same subspaces, and (c) the modes are not perfectly aligned within the common subspace. In all three cases, the errors emerge as a set of angles - and the number of angles associated with each class of error is the same as the number of modes in the sets being compared. The sets of angles can each be combined into a single error angle for each class and ultimately a single angle which reflects the degree of agreement between the measured and computed mode shapes.

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This material has been published in the Journal of Vibration and Control, Vol. 2, No. 2, May 1996, pp. 123-144, the only definitive repository of the content that has been certified and accepted after peer review. Copyright and all rights therein are retained by the Sage Publications.

Link to paper using doi: 10.1177/107754639600200201

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