Assessment of Corrosion Damages with Important Loss of Mass and Influences on the Natural Frequencies of Bending Vibration Modes

Abstract:

Corrosion as material destruction affects the safety of structures, leading to more serious consequences than the simple loss of a mass. The effect of corrosion on the dynamic behaviour of structures act in two ways: the loss of mass increases the natural frequencies, opposite to the effect of stiffness loss. This paper present the results of researches made to extend the mathematical relation presenting the influence of damage location and severity on the natural frequency changes, by adding the effect mass loss. Therefore we modeled the beam once with the discontinuity and loss of mass, afterwards the damaged segment is replaced by an intact one but having the mass similar to that of the damaged segment. This permitted to plot frequency shift curves for both cases and to contrive the relations defining that curves. Finally a relation summarizing the both effects was contrived; it was confirmed both by numerical simulations and experiments.

• Periodical: Applied Mechanics and Materials (Volume 430)
• Pages: 95-100
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.430.95
• Online since: September 2013
• Authors: Gilbert Rainer Gillich, Zeno Iosif Praisach, Daniel Bobos, Cornel Hatiegan
• Keywords: Corrosion, Damage Detection, Mass Loss, Natural Frequency, Stiffness, Vibration

References

[1] SR EN ISO 8044: 2000, Corrosion of metals and alloys - Basic terms and definitions.

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

DOI: 10.1177/058310249803000201

[3] O.S. Salawu, Detection of structural damage through changes in frequency: a review, Engineering Structures, 19(9) (1997) 18-723.

DOI: 10.1016/s0141-0296(96)00149-6

[4] G.R. Gillich, E.D. Birdeanu, N. Gillich, D. Amariei, V. Iancu, C.S. Jurcau, Detection of damages in simple elements, Annals of DAAAM for 2009 & Proceedings of the 20th International DAAAM Symposium,  Book Series: Annals of DAAAM and Proceedings 20 (2009).

[5] G.R. Gillich, Z. Praisach, D.M. Onchis, About the Effectiveness of Damage Detection Methods Based on Vibration Measurements, 3rd WSEAS International Conference on Engineering Mechanics, Structures, Engineering Geology/International Conference on Geography and Geology, Corfu Island, Greece, Jul. 22-24, (2010).

[6] P.R. Roberge, Handbook of corrosion., McGraw-Hill Companies, Inc., (1999).

[7] R. Landolfo, L. Cascini, P. Portioli, Modeling of Metal Structure Corrosion Damage: A State of the Art Report, Sustainability, 2 (2010) 2163-2175.

DOI: 10.3390/su2072163

[8] P. Albrecht, T.T. Hall, Atmospheric corrosion resistance of structural steels, J. Mater. Civil Eng., 15, 2003, pp.2-24.

[9] C.A. Apostolopoulos, D. Michalopoulos, Impact of corrosion on mass loss, fatigue and hardness of BSt500 Steel, Journal of Materials Engineering and Performance, 16(1) (2007) 63-67.

DOI: 10.1007/s11665-006-9009-8

[10] V.G. DeGiorgi, Corrosion Basics and Computer Modelling, in Industrial Application of the BEM, Computational Mechanics Publication, Southampton, (1992).

[11] 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

[12] P. Bratu, Vibratiile sistemelor elastice, Editura Tehnica, Bucuresti, (2000).

[13] Z.I. Praisach, G.R. Gillich, E.D. Birdeanu, Considerations on Natural Frequency Changes in Damaged Cantilever Beams Using FEM, 3rd WSEAS International Conference on Engineering Mechanics, Structures, Engineering Geology/International Conference on Geography and Geology Corfu Island, Greece, Jul 22-24, (2010).