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Active-Sensing Lamb Wave Propagations for Damage Identification in Honeycomb Aluminum Panels
Eric B. Flynn,R. Andrew Swartz,Daniel E. Backman,Gyuhae Park,Charles R. Farrar 한국비파괴검사학회 2009 한국비파괴검사학회지 Vol.29 No.4
This paper presents a novel approach for Lamb wave based structural health monitoring(SHM) in honeycomb aluminum panels. In this study, a suite of three signal processing algorithms are employed to improve the damage detection capability. The signal processing algorithms used include wavelet attenuation, correlation coefficients of power density spectra, and triangulation of reflected waves. Piezoelectric transducers are utilized as both sensors and actuators for Lamb wave propagation. These SHM algorithms are built into a MatLab interface that integrates and automates the hardware and software operations and displays the results for each algorithm to the analyst for side by side comparison. The effectiveness of each of these signal processing algorithms for SHM in honeycomb aluminum panels under a variety of damage conditions is then demonstrated.
Active-Sensing Lamb Wave Propagations for Damage Identification in Honeycomb Aluminum Panels
Flynn, Eric B.,Swartz, R.Andrew,Backman, Daniel E.,Park, Gyu-Hae,Farrar, Charles R. The Korean Society for Nondestructive Testing 2009 한국비파괴검사학회지 Vol.29 No.4
This paper presents a novel approach for Lamb wave based structural health monitoring(SHM) in honeycomb aluminum panels. In this study, a suite of three signal processing algorithms are employed to improve the damage detection capability. The signal processing algorithms used include wavelet attenuation, correlation coefficients of power density spectra, and triangulation of reflected waves. Piezoelectric transducers are utilized as both sensors and actuators for Lamb wave propagation. These SHM algorithms are built into a MatLab interface that integrates and automates the hardware and software operations and displays the results for each algorithm to the analyst for side by side comparison. The effectiveness of each of these signal processing algorithms for SHM in honeycomb aluminum panels under a variety of damage conditions is then demonstrated.
Dispersion curve estimation via phased array beamforming methods
Jarmer, Gregory J,Flynn, Eric B,Todd, Michael D SAGE Publications 2014 Journal of intelligent material systems and struct Vol.25 No.5
<P>Localization of scattering sources via active ultrasonic inspection in plate-like structures requires knowledge of the structure’s dispersion relation and material properties. Often the dispersion relation and material properties are unknown, uncertain, or difficult to model due to material complexity and variability in material properties, geometry, and/or environment, thereby requiring in situ estimation. Two methods are presented for estimating guided wave dispersion curves (phase and group velocity) in a multimodal, multipath environment using a phased array. Phase and group velocities are estimated in situ on an aluminum and carbon fiber plate and compared to theoretical values. Scattering from plate boundaries is localized using the estimated phase and group velocity curves through beamforming and ranging via time of flight.</P>