Comparison of Modal Parameter Estimation Techniques For Experimental Modal Analysis

Comparison of Modal Parameter Estimation Techniques For Experimental Modal Analysis

Paper in proceedings (conference paper)

This paper deals with comparison of three commonly used modal parameter estimation methods (Pick Picking, Least Square Complex Exponential and Eigensystem Realization Algorithm) in order to judge about their accuracy and limitation. There have been invented a great amount of modal parameter estimation techniques in the field of experimental modal analysis. However, there is not universal method which would be suitable for every possible structure and/or with acceptable accuracy. As a test structure, 15 degrees of freedom plane with given mass, damping and stiffness was chosen. The foundations of discussed methods are described, their implementation on the test structure is shown and finally, natural frequencies and damping obtained by analytical approach are compared with those estimated using mentioned techniques. In addition, mode shapes differences are illustrated by means of Modal Assurance Criterion. Based on these comparisons, an accuracy and limitation of the methods is summarized in the conclusion.

This paper deals with comparison of three commonly used modal parameter estimation methods (Pick Picking, Least Square Complex Exponential and Eigensystem Realization Algorithm) in order to judge about their accuracy and limitation. There have been invented a great amount of modal parameter estimation techniques in the field of experimental modal analysis. However, there is not universal method which would be suitable for every possible structure and/or with acceptable accuracy. As a test structure, 15 degrees of freedom plane with given mass, damping and stiffness was chosen. The foundations of discussed methods are described, their implementation on the test structure is shown and finally, natural frequencies and damping obtained by analytical approach are compared with those estimated using mentioned techniques. In addition, mode shapes differences are illustrated by means of Modal Assurance Criterion. Based on these comparisons, an accuracy and limitation of the methods is summarized in the conclusion.

Experimental Modal Analysis, Modal Parameter Estimation, Modal Assurance Criterion

Experimental Modal Analysis, Modal Parameter Estimation, Modal Assurance Criterion

ONDRA, V.; LOŠÁK, P.

12.05.2014

978-80-214-4871-1

ENGINEERING MECHANICS 2014

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