Lamb Wave Polarization Techniques for Structural Damage Localization and Quantification

Abstract : U.S. Army rotorcraft and land-based vehicles develop induced structural damage that requires robust damage diagnostics that characterize these real-time defects. This report investigates one such method based on polarization of guided waves. Initially, an analytical description of polarized Lamb wave components that yield an elliptical, rotated profile of the particle trajectory is provided. A damage localization technique is shown to utilize the elliptical orientation as a damage identification parameter for guided wave structural interrogation techniques. In addition, a damage quantification technique incorporates spatially integrated multiple component mode coefficients that are formulated in the frequency-spatial domain with the intent to better characterize wave reflections and mode conversions. The techniques are applied to finite-element (FE) models of aluminum and composite armor-like structures. Trends from the two-dimensional FE numerical studies are verified by a threedimensional scanning laser vibrometry test setup for the undamaged case. Recommendations of implementing the polarization techniques for damage localization and quantification on Army platforms are given.

[1]  James Ayers,et al.  Phase Gradient and Mode Conversion Estimation in 1D Damaged Structures , 2011 .

[2]  D.W. Greve,et al.  Interaction of defects with lamb waves in complex geometries , 2005, IEEE Ultrasonics Symposium, 2005..

[3]  Hoon Sohn,et al.  Applications of an Instantaneous Damage Detection Technique to Plates with Additional Complexities , 2010 .

[4]  F. Fedorov.  Theory of Elastic Waves in Crystals , 1968 .

[5]  G. Müller,et al.  Theory of elastic waves , 2007 .

[6]  Massimo Ruzzene,et al.  Frequency–wavenumber domain filtering for improved damage visualization , 2007 .

[7]  Fu-Kuo Chang,et al.  Structural Health Monitoring , 2016 .

[8]  Sabu John,et al.  Damage detection in T-joint composite structures , 2006 .

[9]  Keith Worden,et al.  Signal Processing for Damage Detection , 2009 .

[10]  C. Farrar,et al.  Health Monitoring of UAV Wing Skin-to-spar Joints using Guided Waves and Macro Fiber Composite Transducers , 2007 .

[11]  I. J. Oppenheima,et al.  Lamb Wave Behavior in Bridge Girder Geometries , 2008 .

[12]  Anindya Ghoshal,et al.  Methods of distributed sensing for health monitoring of composite material structures , 2001 .

[13]  Coupling of Lamb waves at a tee junction , 1999, 1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027).

[14]  Richard Loendersloot,et al.  Vibration based Structural Health Monitoring of a Composite Plate Structure with Multiple Stiffeners , 2010 .

[15]  Massimo Ruzzene,et al.  Multiple component mode conversion coefficients via Lamb wave polarization measurements , 2011, Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.