Increasing the scanning range of Lamb wave based SHM systems by optimizing the actuator–sensor design

Piezoelectric induced ultrasonic Lamb waves can easily be used for the development of structural health monitoring systems for aircraft and other thin-walled structures. The reduction of the excited wave amplitudes depends mainly on the traveling distance and the material damping, especially in composite materials which restricts the maximum scanning distance between a piezoelectric actuator and a sensor. But there are several possibilities to increase the scanning range of Lamb waves. In the present paper, the focus is on the influence of the adhesive layer and the resonances of the actuator to increase the amplitudes of the excited wave. The objective is to excite Lamb waves with higher amplitudes without increasing the electrical energy for the wave excitation. In the paper, a numerical optimization is proposed which aims at increasing the wave amplitudes by optimizing sensor parameters and the excitation frequency. It has been found that small changes in the geometry of the piezoelectric actuator patch and the use of an optimized excitation frequency elevate the amplitudes of waves significantly.

[1]  Rolf Lammering,et al.  Investigation on piezoelectrically induced Lamb wave generation and propagation , 2007 .

[2]  F. P. Wolf.  Präzisionsmessungen des Elastizitätsmoduls von Polymeren mit Longitudinalschwingungen II. Teil: Apparatur und Ergebnisse , 1979 .

[3]  Fu-Kuo Chang,et al.  Adhesive interface layer effects in PZT-induced Lamb wave propagation , 2010 .

[4]  Thomas Bäck,et al.  Evolutionary algorithms in theory and practice - evolution strategies, evolutionary programming, genetic algorithms , 1996 .

[5]  Hans-Paul Schwefel,et al.  Evolution and optimum seeking , 1995, Sixth-generation computer technology series.

[6]  H. Lamb.  On waves in an elastic plate , 1917 .

[7]  Victor Giurgiutiu,et al.  7 – PIEZOELECTRIC WAFER ACTIVE SENSORS , 2008 .

[8]  Christian Willberg,et al.  Simulation of Piezoelectric Induced Lamb Waves in Plates , 2009 .

[9]  Mark M. Derriso,et al.  The effect of actuator bending on Lamb wave displacement fields generated by a piezoelectric patch , 2008 .

[10]  Sungwon Ha.  Modeling Lamb wave propagation induced by adhesively bonded PZTs on thin plates , 2009 .

[11]  Christian Willberg,et al.  Experimental and Theoretical Analysis of Lamb Wave Generation by Piezoceramic Actuators for Structural Health Monitoring , 2012 .

[12]  Ivan Bartoli,et al.  Modeling guided wave propagation with application to the long-range defect detection in railroad tracks , 2005 .

[13]  T. H. Brockmann.  Theory of Adaptive Fiber Composites , 2009 .

[14]  J. Sirohi,et al.  Fundamental Understanding of Piezoelectric Strain Sensors , 1999, Smart Structures.

[15]  Tobias H. Brockmann,et al.  Theory of Adaptive Fiber Composites: From Piezoelectric Material Behavior to Dynamics of Rotating Structures , 2009 .

[16]  Jung-Ryul Lee,et al.  Structural health monitoring for a wind turbine system: a review of damage detection methods , 2008 .

[17]  F. P. Wolf.  Präzisionsmessungen des Elastizitätsmoduls von Polymeren mit Longitudinalschwingungen , 1979 .

[18]  Christian Boller,et al.  Health Monitoring of Aerospace Structures , 2003 .

[19]  Lin Ye,et al.  Guided Lamb waves for identification of damage in composite structures: A review , 2006 .

[20]  Ingo Rechenberg,et al.  Evolutionsstrategie '94 , 1994, Werkstatt Bionik und Evolutionstechnik.

[21]  Chee Kiong Soh,et al.  Electromechanical Impedance Modeling for Adhesively Bonded Piezo-Transducers , 2004 .

[22]  S. Spearing,et al.  In-Situ Damage Detection of Composites Structures using Lamb Wave Methods , 2002 .

[23]  I. A. Viktorov.  Rayleigh and Lamb Waves , 1967 .

[24]  Mircea Calomfirescu.  Lamb Waves for Structural Health Monitoring in Viscoelastic Composite Materials , 2008 .

[25]  Dragan Marinkovic.  A new finite composite shell element for piezoelectric active structures , 2007 .

[26]  S. R. Olsen,et al.  An in situ rapid heat–quench cell for small-angle neutron scattering , 2008 .

[27]  E. Crawley,et al.  Use of piezoelectric actuators as elements of intelligent structures , 1987 .