Damage Detection in Flux Cored Wire Welded Structures by Using Vibration Testing

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Abstract:

In welded structures subjected to dynamic cyclic loads may appear and propagate fatigue cracks due to local structural damage. These cracks may initiate due to technological damages induced by welding process, or by environmental operating conditions. In the present work, it is determined, by the means of Finite Element Method (FEM), the natural frequencies and mode shapes of more steel specimens that are welded together. The analysis is carried out in undamaged condition as well as in damaged one, after the damage has been artificially induced. The experimental measurement of the vibration response is carried out by using a condenser semi-professional microphone Samson C01U, which is suitable for high-fidelity acoustic measurements in the frequency range of 40 18.000 Hz. A first post-processing of the vibration responses of the welded specimens, in free-free conditions, is carried out using an algorithm based on Prony series. A second post-processing is carried out by means of signal processing using DWT together with Shannon entropy. The results are compared to modal parameters estimated using FE Analysis.

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Solid State Phenomena (Volume 216)

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110-115

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August 2014

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© 2014 Trans Tech Publications Ltd. All Rights Reserved

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[1] N.M.M. Maia, J.M.M. Silva, E.A.M. Almas, R.P.C. Sampaio, Damage detection in structures: from mode shape to frequency response methods, Mech. Sys. Sig. Proc., 17(2003), 489–498.

DOI: 10.1006/mssp.2002.1506

Google Scholar

[2] N.M.M. Maia, J.M.M. Silva, R.P.C. Sampaio, Localization of damage using curvature of the frequency-response-functions, Proc. of 15th Int. Modal Analysis Conference, (1997), 942-946.

Google Scholar

[3] M. Palacz, M. Krawczuk, Vibration parameters for damage detection in structures, J. Sound. Vib., 249(2002), 999-1010.

DOI: 10.1006/jsvi.2001.3761

Google Scholar

[4] D.G. Shang, M.E. Barkley, Y. Wang, T.C. Lim, Effect of fatigue damage on dynamic response frequency of spot-welded joints, Int. Journal of Fatigue, 25(2003), 311-316.

DOI: 10.1016/s0142-1123(02)00140-8

Google Scholar

[5] S.L. Hu, J.P. Li,H.T. Vincent, H. Li, Modal parameter estimation for jacket-type platforms using free-vibration data,J. waterw. port. coast. oc. eng., ASCE – Sept/Oct (2011), 234-245.

DOI: 10.1061/(asce)ww.1943-5460.0000089

Google Scholar

[6] D. Potts, M. Tasche, Parameter estimation for exponential sums by approximate Prony method, Sig. Proc., 90(2010), 1631–1642.

DOI: 10.1016/j.sigpro.2009.11.012

Google Scholar

[7] C.E. Shannon, A mathematical theory of communication, reprinted by The Bell System Technical Journal, 27(1948), 379–423 and 623–656.

DOI: 10.1002/j.1538-7305.1948.tb00917.x

Google Scholar