Reciprocity in Experimental Modal Analysis

Peter Pavelka^1, , Róbert Huňady¹, Martin Hagara¹ and František Trebuňa¹

¹Department of Applied Mechanics and Mechanical Engineering, Faculty of Mechanical Engineering, Letná 9, 042 00 Košice, Slovakia

Cite this paper:
Peter Pavelka, Róbert Huňady, Martin Hagara and František Trebuňa. Reciprocity in Experimental Modal Analysis. American Journal of Mechanical Engineering. 2015; 3(6):252-256. doi: 10.12691/ajme-3-6-20

Abstract

This paper deals with modal analysis and estimation of modal parameters of an analyzed structure. An aim of the paper is to verify one of four basic assumptions considered in modal testing. This property is reciprocity. Reciprocity means that the frequency response function measured between two degrees-of-freedom must be the same regardless of which degree-of-freedom is input or output. In the paper the experimental and numerical modal analysis of a cantilever beam are presented. There are described two experimental measurements focused on reciprocity of measurement process. Measured mode shapes are compared to each other using Cross Modal Assurance Criterion. The results of experimental and numerical modal analysis are compared to each other.

Keywords:
experimental modal analyses reciprocity cantilever beam cross MAC CMIF

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]	F. Trebuňa, F. Šimčák, R. Huňady.: Vibration and modal analysis of mechanical systems, (In Slovak), Typopress, Košice, 2012.
[2]	A. Bilošová.: Experimental modal analysis, (In Czech), VŠB TU Ostrava.
[3]	R. J. Allemang, D. L. Brown: A complete review of the complex mode indicator function with applications. International Conference on Noise and Vibration Engineering, ISMA, (2006), 38 pp.
[4]	D. J. Ewins: Modal testing – Theory, practice and application. 2. edition, Wiley, (2000).
[5]	R. Huňady, M.Hagara:Experimental Investigation of Mode Shapes of Symmetric Structures, In: Acta Mechanica Slovaca, Vol 19, No. 3, 2015, 12-17 p.
[6]	R. J. Allemang: The Modal Assurance Criterion (MAC): Twenty Years of Use and Abuse, Sound & Vibration, August, 2003, pp. 14-21.