Structural Reanalysis of Dynamic Systems Using Model Updating Method

Kyoung-Bong Han

.

DOI: 10.4236/eng.2011.310122                

Abstract

Model updating methodologies are invariably successful when used on noise-free simulated data, but tend to be unpredictable when presented with real experimental data that are unavoidably corrupted with uncorrelated noise content. In this paper, reanalysis using frequency response functions for correlating and updating dynamic systems is presented. A transformation matrix is obtained from the relationship between the complex and the normal frequency response functions of a structure. The transformation matrix is employed to calculate the modified damping matrix of the system. The modified mass and stiffness matrices are identified from the normal frequency response functions by using the least squares method. A numerical example is employed to illustrate the applicability of the proposed method. The result indicates that the present method is effective.

Keywords

Model Updating, Reanalysis, Frequency Response Functions, Transformation Matrix, Damping Matrix

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	H. G. Natke, “Updating Computation Models in the Frequency Domain Based on Measured Data: A Survey,” Probabilistic Engineering Mechanics, Vol. 3, 1988, pp. 8-35. doi:10.1016/0266-8920(88)90005-7
[2]	R. M. Lin and D. J. Ewins, “Model Updating Using FRF Data,” Proceedings of ISMA, Vol. 15, 1990, pp. 141-163.
[3]	M. Imregun and W. J. Visser, “A Review of Model Updating Techniques,” Shock and Vibration Digest, Vol. 23, No. 1, 1991, pp. 9-20. doi:10.1177/058310249102300102
[4]	J. E. Mottershead and M. I. Friswell, “Model Updating in Structural Dynamics: A Survey,” Journal of Sound and Vibration, Vol. 167, 1995, pp. 347-375. doi:10.1006/jsvi.1993.1340
[5]	A. Bhasiar, S. S. Sahu and B. C. Nakra, “Approximations and Reanalysis over Parameter Interval for Dynamic Design,” Journal of Sound and Vibration, Vol. 248, No. 1, 2001, pp. 178-186. doi:10.1006/jsvi.2001.3686
[6]	C. Mares, J. E. Mottershead and M. I. Friswell, “Stochastic Model Updating: Part 1—Theory and Simulated Example,” Mechanical Systems and Signal Processing, Vol. 20, No. 7, 2006, pp. 1674-1695. doi:10.1016/j.ymssp.2005.06.006
[7]	C. Joao, N. D. Biswa, G. Abhijit and L. Maitreya, “A Direct Method for Model Updating with Incomplete Measured Data and without Spurious Modes,” Mechanical Systems and Signal Processing, Vol. 21, No. 7, 2007, pp. 2715-2731. doi:10.1016/j.ymssp.2007.03.001
[8]	E. Capiez-Lernout and C. Soize, “Robust Updating of Uncertain Damping Models in Structural Dynamics for Low- and Me-dium-Frequency Ranges,” Mechanical Systems and Signal Processing, Vol. 22, No. 8, 2008, pp. 1774-1792. doi:10.1016/j.ymssp.2008.02.005
[9]	V. Arora, S. P. Singh and T. K. Kundra, “Further Experience with Model Updating Incorporating Damping Matrices,” Mechanical Systems and Signal Processing, Vol. 24, No. 5, 2010, pp. 1383-1390. doi:10.1016/j.ymssp.2009.12.010
[10]	S. R. Ibrahim and A. Sestieri, “Analysis of Errors and Approximations in the Use of Modal Coordinates,” Journal of Sound and Vibration, Vol. 177, No. 2, 1994, pp. 145-157. doi:10.1006/jsvi.1994.1424
[11]	F. Lembregts and M. Brughmans, “Estimation of Real Modes from FRFs via Direct Parameter Identification,” Proceedings of 7th International Modal Analysis Conference, Las Vegas, 30 January 1989, pp. 631-636.