Non-Contact Generation and Reception of Guided Waves Using Near-Field Inductive Coupling *

Wafer-type PZT transducers are widely used for generation and detection of elastic guided waves. In this study, an inductively-coupled transformer system, which consists of primary and secondary ferrite-core coils, is developed for near-field transmission of the excitation waveform and guided wave response signals. An ultrasonic wave is excited by coupling a pulse waveform from the primary coil to a secondary coli connected to a PZT wafer. The secondary coil is affixed to the PZT wafter and consequently to the test specimen where the PZT wafer is mounted. Then, the guided waves generated by the PZT wafer and reflected from the boundaries of the test specimen are transmitted back to the primary coil. Three progressive versions of the transform systems are presented. The feasibility of the proposed inductively coupled transformer systems is demonstrated by comparing the performance of the proposed contactless system with a conventional wired system.

[1]  Hoon Sohn,et al.  Wavelet-based active sensing for delamination detection in composite structures , 2004 .

[2]  S. Grondel,et al.  Damage assessment in composites by Lamb waves and wavelet coefficients , 2003 .

[3]  Seth S. Kessler,et al.  Experimental Application of Optimized Lamb Wave Actuating/Sensing Patches for Health Monitoring of Composite Structures , 2003 .

[4]  Hoon Sohn,et al.  Active sensing with an inductively coupled (wireless) Lamb wave transducer , 2006 .

[5]  Victor Giurgiutiu,et al.  Lamb wave generation with piezoelectric wafer active sensors for structural health monitoring , 2003, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[6]  Alison B. Flatau,et al.  Review Paper: Health Monitoring of Civil Infrastructure , 2003 .

[7]  Hoon Sohn,et al.  A Review of Structural Health Review of Structural Health Monitoring Literature 1996-2001. , 2002 .

[8]  Hoon Sohn,et al.  An inductively coupled (wireless) lamb wave transducer , 2006 .

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

[10]  C.P. Yue,et al.  An Inductively Coupled Lamb Wave Transducer , 2007, IEEE Sensors Journal.

[11]  J. Rose,et al.  Lamb wave scattering analysis for reflector characterization , 1997, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[12]  Emmanuel Moulin,et al.  Piezoelectric transducer embedded in a composite plate: Application to Lamb wave generation , 1997 .

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

[14]  David W. Greve,et al.  Lamb wave behavior in bridge girder geometries , 2006, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[15]  Daniel J. Inman,et al.  Manufacturing and Mechanics-Based Characterization of Macro Fiber Composite Actuators , 2002 .