Enhancement of Lamb wave–based in situ structural health monitoring through guided local geometry changes

Abstract

The incorporation of in situ structural health monitoring is currently an afterthought used to address critical areas identified in testing or service. This article investigates the use of local geometry changes to improve detectability of damage in the form of a line crack at a given fatigue critical location. A methodology encompassing especially developed Lamb wave tools is presented, which may allow the implementation of in situ structural health monitoring at the design stage of critical structures. A systematic redesign will be presented based on Lamb wave technology, which has been enabled by high-speed ray-trace modelling. By modelling propagation of wavefronts as rays, the high cost of iterating designs in finite element or experimental methods can be overcome. Implementing the ray-trace modelling, optimized design changes lead to improved damage sensitivity. Damage sensitivity has been quantified through well-used scatter/difference techniques. This was followed by analysing the strength and stiffness of the redesigned structures to reveal any consequential changes. To demonstrate the efficacy of this proposed methodology, a case study is presented where the fatigue critical location of structure representing the lower wing skin of an aircraft structure is analysed.

Keywords

Lamb wave structural health monitoring local geometry damage detection in situ

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References

Staszewski

Lee

Traynor

. Fatigue crack detection in metallic structures with Lamb waves and 3D laser vibrometry. Meas Sci Technol 2007; 18(3): 727–739.

Alleyne

Cawley

. The interaction of Lamb waves with defects. IEEE T Ultrason Ferro 1992; 39(3): 381–397.

Ryles

Ngau

McDonald

. Comparative study of nonlinear acoustic and Lamb wave techniques for fatigue crack detection in metallic structures. Fatigue Fract Eng M 2008; 31(8): 674–683.

Diamanti

Soutis

Hodgkinson

. Non-destructive inspection of sandwich and repaired composite laminated structures. Compos Sci Technol 2005; 65(13): 2059–2067.

Diamanti

Soutis

Hodgkinson

. Piezoelectric transducer arrangement for the inspection of large composite structures. Compos Part A: Appl S 2007; 38(4): 1121–1130.

Pavlopoulou

Soutis

Staszewski

. Structural health monitoring of composite scarf repairs with guided waves. Struct Health Monit 2012; 518: 328–337.

Doherty

Chiu

. Scattering of ultrasonic-guided waves for health monitoring of fuel weep holes. Struct Health Monit 2011; 11(1): 27–42.

Ong

Chiu

. An optical approach to guiding Lamb waves in plates for design for structural health monitoring. In: Asia Pacific workshop on structural health monitoring, Tokyo, Japan, 30 November – 2 December 2010.

Ong

Chiu

. Damage Quantification in Plates Using Lamb Waves [online]. In: Proceedings of the 6th Australasian Congress on Applied Mechanics (eds Kian

Teh

Ian

Davies

Ian

Howard

), Perth, WA: Engineers Australia, 2010, pp. 402–411.

10.

Baker

. Structural health monitoring of a bonded composite patch repair on a fatigue-cracked F-111C wing. Melbourne, VIC, Australia: Defence Science and Technology Organisation, 2008.

11.

Baker

Rajic

Davis

. Towards a practical structural health monitoring technology for patched cracks in aircraft structure. Compos Part A: Appl S 2009; 40(9): 1340–1352.

12.

Wong

CKW

Chiu

Rajic

. Can stress waves be used for monitoring sub-surface defects in repaired structures. Compos Struct 2006; 76(3): 199–208.

13.

Teo

Chiu

Chang

. Optimal placement of sensors for sub-surface fatigue crack monitoring. Theor Appl Fract Mec 2009; 52(1): 40–49.

14.

Chiu

Tian

Chang

. The effects of structural variations on the health monitoring of composite structures. Compos Struct 2009; 87(2): 121–140.

15.

Coelho

Kim

. Optimal sensor placement for active guided wave interrogation of complex metallic components. In: Proceedings of the SPIE: sensors and smart structures technologies for civil, mechanical, and aerospace systems, San Diego, CA, 7–10 March 2011, vol. 7981.

16.

Kessler

Spearing

Soutis

. Damage detection in composite materials using Lamb wave methods. Smart Mater Struct 2002; 11(2): 269–278.

17.

Ong

Chiu

. Redirection of Lamb waves for structural health monitoring. Smart Mater Res 2012; 2012: 718686.

18.

Viktorov

. Rayleigh and Lamb waves: physical theory and applications (ultrasonic technology). New York: Plenum Press, 1967, x, 154 pp.

19.

Hay

Royer

Gao

. A comparison of embedded sensor Lamb wave ultrasonic tomography approaches for material loss detection. Smart Mater Struct 2006; 15(4): 946–951.

20.

Jeong

Lee

Bae

. Defect detection and localization in plates using a lamb wave time reversal technique. Int J Precis Eng Man 2011; 12(3): 427–434.

21.

Lissenden

Cho

Kim

. Fatigue crack growth monitoring of an aluminum joint structure. In: Review of progress in quantitative nondestructive evaluation (1211), vols 29a and 29b (eds Thompson

Chimenti

). AIP, 26–31 July 2009, Kingston (Rhode Island), pp. 1868–1875. DOI: http://dx.doi.org/10.1063/1.3362323

22.

Song

Huang

. Online guided wave-based debonding detection in honeycomb sandwich structures. AIAA J 2012; 50(2): 284–293.

23.

. Identification of damage using Lamb waves from fundamentals to applications (lecture notes in applied and computational mechanics), vol. 48. Berlin: Springer-Verlag, 2009, 346 pp.

24.

Nieuwenhuis

Neumann

Greve

. Generation and detection of guided waves using PZT wafer transducers. IEEE T Ultrason Ferro 2005; 52(11): 2103–2111.

25.

Staszewski

Lee

Mallet

. Structural health monitoring using scanning laser vibrometry. Part I: Lamb wave sensing. Smart Mater Struct 2004; 13(2): 251–260.

26.

Rajic

Rosalie

. A feasibility study into the active smart patch concept for composite bonded repairs. Report no. DSTO-TR-2247, August 2008. Australia: Fishermans Bend, Victoria. Defence Science and Technology Organisation.