On the Use of Higher-Order Frequencies in Crack Identification in Columns Subjected to Important Tip Mass

Abstract:

The paper present a novel non-destructive evaluation method designed to assess damage in structural elements subjected to important axial loads, as columns are. In the prior research a reliable damage detection method was developed for beams subjected to own mass, that consider the relation existing between the energy stored in the beam in certain vibration modes and the related natural frequencies. First we found the mathematical relations expressing the healthy pillar mode shapes and frequencies with respect to the top mass. Afterward, by means of FEM, we derived the natural frequencies for the numerous damage cases, in order to define the frequency shift curves. Analogous to the case of beams, the damage location is characterized by patterns that are derived from the mode shape curvatures square of the healthy beam. The damage location becomes an inverse problem while the damage position is found by interpreting frequency measurements made on the healthy and damaged beam.

• Periodical: Applied Mechanics and Materials (Volume 801)
• Pages: 148-153
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.801.148
• Online since: October 2015
• Authors: Gilbert Rainer Gillich, Florian Muntean, Codrin Nistor Nitescu, Vasile Iancu, Zeno Iosif Praisach*, Zoltan Iosif Korka
• Keywords: Crack Identification, FEM Analysis, Natural Frequencies, Vibration Modes

References

[1] A. Morassi, F. Vestroni, Dynamic Methods for Damage Detection in Structures, CISM Courses and Lectures, Vol. 499, Springer Wien New York, (2008).

[2] S.W. Doebling, C.R. Farrar, M.B. Prime, A summary review of vibration based damage identification methods, Shock Vibration Digest, 30(2), 1998, pp.91-105.

DOI: 10.1177/058310249803000201

[3] G.R. Gillich, Z.I. Praisach, I. Negru, Damages influence on dynamic behaviour of composite structures reinforced with continuous fibers, Materiale Plastice 49(3), 2012, pp.186-191.

[4] G.R. Gillich, Z.I. Praisach, M.A. Wahab, O. Vasile, Localization of Transversal Cracks in Sandwich Beams and Evaluation of Their Severity, Shock Vib. (2014) Article Number: 607125.

DOI: 10.1155/2014/607125

[5] E. Ekinovic, An approximate technique for damage identification in beams using shifts in natural frequencies, Proceedings of The 22nd International Conference on Noise and Vibration Engineering, Leuven, Belgium, 2010 September 20-22, Leuven (2010).

[6] G.R. Gillich, Z.I. Praisach, Modal identification and damage detection in beam-like structures using the power spectrum and time–frequency analysis, Signal Process. 96 (2014) 29–44.

DOI: 10.1016/j.sigpro.2013.04.027

[7] G. Yan, A. de Stefano, E. Matta, R. Feng A novel approach to detecting breathing-fatigue cracks based on dynamic characteristics, J. Sound Vib. 332 (2013) 407–422.

DOI: 10.1016/j.jsv.2012.09.008

[8] G.R. Gillich, Z.I. Praisach, Robust method to identify damages in beams based on frequency shift analysis, Conference on Health Monitoring of Structural and Biological Systems, San Diego, CA, March 12-15, 2012, Article Number: 83481D.

DOI: 10.1117/12.915158

[9] C. Liang, H. Deng, J. Zhang, L. Yu, Vibration studies of simply supported beam based on binocular stereo vision, International Symposium on Precision Engineering Measurement and Instrumentation (2015) 94463M.

DOI: 10.1117/12.2181390

[10] G.R. Gillich, Z.I. Praisach, C.M. Iavornic, Reliable method to detect and assess damages in beams based on frequency changes, Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference 2012, VOL 1, PTS A and B, (2012).

DOI: 10.1115/detc2012-70094