Volume 19, Issue No.3

KEY WORDS

Symmetric structure; coupled modes; experimental modal analysis; complex mode indicator function

ABSTRACT

Paper deals with experimental determination of modal parameters of symmetric structures which have so-called coupled mode shapes of vibration.
These modes usually have almost the same frequencies. This is why it could be difficult to identify them from frequency response functions where their peaks overlap. Main attention is focused on the using of Complex Mode Indicator Function (CMIF) that is able to separate coupled and also closely spaced modes by using singular value decomposition of multiple reference FRF matrix. In the paper there is described a theoretical background of CMIF and its application in spatial domain parameter estimation. Its functionality is explained on an analytical model of mechanical system of six degrees of freedom. Its practical application is presented by experimental modal analysis of circular saw blade.

CITATION INFORMATION

Acta Mechanica Slovaca. Volume 19, Issue 3, Pages 12–17, ISSN 1335-2393

DOWNLOAD

  Experimental Investigation of Mode Shapes of Symmetric Structures

REFERENCES

[1] Trebuňa, F., Huňady, R., Bobovský, Z., Hagara, M.: An Application of High-speed Digital Image Correlation id Determination of Modal Parameters. In: Acta Mechancia Slovaca, Vol.15, No. 4., 2011, pages 6-13.

[2] Trebuňa, F., Šimčák, F., Huňady, R.: Experimental Analysis of Vibration of Transport Complex for Transportation of Spent Nuclear Fuel. In: Acta Mechancia Slovaca, Vol. 16, No. 3., 2012, pages 26-32

[3] Trebuňa, F., Huňady, R., Pástor, M., Binda, M.: Analysis of Causes Unwanted Dynamical Phenomenon on Output Pipes of Turbocompressor. In: Acta Mechancia Slovaca, Vol. 15, No. 3., 2011, pages 6-13

[4] Philips, A.W., Allemang, R.J., Fladung, W.A. (1998) The Complex Mode Indicator Function (CMIF) as a Parameter Estimation Method. 16th International Modal Analysis Conference, IMAC XVI, 6 pp.

[5] Allemang, R.J., Brown, D.L. (2002) Chapter 21: Experimental Modal Analysis. In: Harris, C.M., Piersol, A.G., Harris' Shock and Vibration Handbook, McGraw-Hill Inc., 1568 pp

[6] Allemang, R.J., Brown, D.L. (2006) A complete review of the complex mode indicator function with applications. International Conference on Noise and Vibration Engineering, ISMA, 38 pp.

[7] Trebuňa, F., Šimčák, F., Huňady, R. (2012) Vibration and Modal Analysis of Mechanical Systems (in Slovak), TU v Košiciach, Košice, 236 pp

[8] Ewins, D.J. (2000) Modal testing: theory, practice and application. Second edition. Wiley, 562 pp

Latest Issue

ams 2 2016

Download