A Method for Acoustic Emission Source Identification Based on Optimisation

Abstract:

When a metal or composite structure begins to fail, for example due to high cycle fatigue, acoustic emissions caused by the propagation of cracks give rise to bursts of ultrasonic waves travelling through the structure. The health of a structure can be monitored by means of sensors which detect these waves. Acoustic emissions are often generated in experiments by breaking a pencil lead against the surface of the structure in a standardised way but the forces that this imparts are not well understood at present. A Local Interaction Simulation Approach (LISA) algorithm has been implemented to simulate the propagation of ultrasonic waves. This code has been validated against experiments in previous work and has been shown to accurately reproduce the propagation of Lamb waves (including reflections and dispersion etc.) within thin-plate like structures. This paper deals with the use of the LISA code to characterise the forces associated with standard pencil lead breaks. The displacement due to waves emanating from a break is measured and a Differential Evolution (DE) optimisation scheme is used to find the optimal profile of forcing to match the simulation with experiment.

• Periodical: Key Engineering Materials (Volumes 413-414)
• Pages: 793-801
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.413-414.793
• Online since: June 2009
• Authors: Andrew Spencer, Keith Worden, Gareth Pierce
• Keywords: Acoustic Emission (AE), Differential Evolution (DE), Local Interaction Simulation Approach (LISA), Source Identification

References

[1] J.L. Rose, Ultrasonic Waves in Solid Media, Cambridge University Press, (2004).

[2] Viktorov I, Rayleigh and Lamb Waves: Physical Theory and Applications, Plenum Press, New York, (1970).

[3] D.N. Alleyne, P. Cawley, P. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 39, (1992), p.381.

[4] A.J. Croxford, P.D. Wilcox, B.W. Drinkwater, G. Konstantinidis. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Volume 463, (2007), p.2961.

DOI: 10.1098/rspa.2007.0048

[5] D.J. Buttle, C.B. Scruby, Characterization of fatigue of aluminum alloys by acoustic emission. I : identification of source mechanism, Journal of Acoustic Emission, (1990).

DOI: 10.1016/0963-8695(92)90675-7

[6] A. Balikin, . umerical simulation of guided waves for SHM - a literature survey, UPSSP Platform Grant Report, Dynamics Research Group, Department of Mechanical Engineering, University of Sheffield, (2007).

[7] P.P. Delsanto, T. Whitcombe, H.H. Chaskelis, R.B. Mignogna. Wave Motion, Vol. 16, (1992), p.65.

DOI: 10.1016/0165-2125(92)90047-6

[8] P.P. Delsanto, R.S. Schechter, H.H. Chaskelis, R.B. Mignogna, R. Kline. Wave Motion, Vol. 20, (1994) p.295.

DOI: 10.1016/0165-2125(94)90016-7

[9] P.P. Delsanto, R.S. Schechter, R.B. Mignogna. Wave Motion, Vol. 26, (1997), p.329.

[10] B.C. Lee, W.J. Staszewski. Smart Materials and Structures. Vol. 16, (2007), p.249.

[11] B.C. Lee, W.J. Staszewski. Smart Materials and Structures. Vol. 16, (2007), p.260.

[12] A.B. Spencer, K. Worden, S.G. Pierce, J.J. Hensman, D. Chetwynd, W.J. Staszewski. In Proceedings of 23rd International Conference on Noise and Vibration Engineering, Leuven, (2008).

[13] N.N. Hsu, Acoustic Emissions Simulator, US Patent 4, 018, 084, (1977).

[14] A.C. Eringen, E.S. Suhubi, Elastodynamics Vol 1, Academic Press, New York, (1974).

[15] R. Storn, R. Price. Journal of Global Optimization, Vol. 11, (1997), p.341.