Original scientific paper

https://doi.org/10.17559/TV-20140928193641

The role of singular values of measured frequency response function matrix in modal damping estimation (Part I: Theory)

Ferenc Pápai orcid.org/0000-0003-4808-0882 ; Budapest University of Technology and Economics, Faculty of Transportation Engineering and Vehicle Engineering, Department of Vehicle Elements and Vehicle-Structure Analysis, H-1111 Budapest, Stoczek u. 2., Hungary
István Szűcs ; University of Pécs, Pollack Mihály Faculty of Engineering and Information Technology, Department of Infrastructure and Technical Geoinformatics, H-7624 Pécs, Boszorkány u. 2., Hungary

Abstract

The singular value decomposition of the measured frequency response function matrix, as a very effective tool of experimental modal analysis is used over the last twenty-five years. The complex mode indication function has become a common numerical tool in processing experimental data. There are many references on the development of complex mode indication function including the enhanced mode indication function and its use together with the enhanced frequency response function to form spatial domain modal parameter estimation methods. Another amendment of the enhanced mode indicator function method is the extension of the single degree-of-freedom aspects of the complex mode indication function method to include a limited number of modes. In the paper, methods for estimation of damped eigen frequencies, modal damping and mode shapes are presented that are based on singular value decomposition of frequency response function matrix. It is shown how to obtain phase information for the complex mode indication function, in order to use the standard single degree-of-freedom modal parameter estimation methods. New aggregated frequency response function is introduced. A least-squares approximation will be presented for eliminating the error caused by frequency discretization. Analytical models and examples taken from vehicle industry are also used to demonstrate applications of the aggregated frequency response function method and estimation of modal damping.

Keywords

complex mode indication function; damping estimate; experimental modal analysis; frequency response function matrix; singular values decomposition

Hrčak ID:

139758

URI

https://hrcak.srce.hr/139758

Publication date:

15.6.2015.

Article data in other languages: croatian

Visits: 3.207 *