Lamb wave attenuation in a rough plate. II. Analytical and numerical results in a fluid plate

2008 ◽  
Vol 104 (7) ◽  
pp. 074909 ◽  
Author(s):  
Catherine Potel ◽  
Damien Leduc ◽  
Bruno Morvan ◽  
Claude Depollier ◽  
Anne-Christine Hladky-Hennion ◽  
...  
Keyword(s):  
Lamb Wave ◽  
Wave Attenuation ◽  
Numerical Results ◽  
Rough Plate

Lamb wave attenuation in a rough plate. I. Analytical and experimental results in an anisotropic plate

2008 ◽  
Vol 104 (7) ◽  
pp. 074908 ◽  
Author(s):  
Catherine Potel ◽  
Damien Leduc ◽  
Bruno Morvan ◽  
Claude Depollier ◽  
Anne-Christine Hladky-Hennion ◽  
...  
Keyword(s):  
Lamb Wave ◽  
Anisotropic Plate ◽  
Wave Attenuation ◽  
Experimental Results ◽  
Rough Plate

scholarly journals Integrated Structural Health Assessment Using Piezoelectric Active Sensors

2005 ◽  
Vol 12 (6) ◽  
pp. 389-405 ◽  
Author(s):  
Jeannette R. Wait ◽  
Gyuhae Park ◽  
Charles R. Farrar
Keyword(s):  
Lamb Wave ◽  
Structural Damage ◽  
Structural Integrity ◽  
Damage Identification ◽  
Wave Attenuation ◽  
Health Assessment ◽  
Mechanical Impedance ◽  
Integrated Approach ◽  
Impedance Method ◽  
Sensing Technology

This paper illustrates an integrated approach for identifying structural damage. The method presented utilizes piezoelectric (PZT) materials to actuate/sense the dynamic response of the structures. Two damage identification techniques are integrated in this study, including impedance methods and Lamb wave propagations. The impedance method monitors the variations in structural mechanical impedance, which is coupled with the electrical impedance of the PZT patch. In Lamb wave propagations, one PZT patch acting as an actuator launches an elastic wave through the structure, and responses are measured by an array of PZT sensors. The changes in both wave attenuation and reflection are used to detect and locate the damage. Both the Lamb wave and impedance methods operate in high frequency ranges at which there are measurable changes in structural responses even for incipient damage such as small cracks, debonding, or loose connections. The combination of the local impedance method with the wave propagation based approach allows a better characterization of the system’s structural integrity. The paper concludes with experimental results to demonstrate the feasibility of this integrated active sensing technology.

Numerical and Experimental Studies on the Scattering of Lamb Waves in a Bent Plate

2006 ◽  
Vol 321-323 ◽  
pp. 770-775
Author(s):  
Arief Gunawan ◽  
Sohichi Hirose
Keyword(s):  
Experimental Study ◽  
Outer Surface ◽  
Lamb Wave ◽  
Lamb Waves ◽  
Ultrasonic Method ◽  
Experimental Studies ◽  
Numerical Results ◽  
Bent Plate ◽  
Bent Plates

Scattering analysis of Lamb waves in perpendicularly bent plates with and without a crack is presented. Single cracks on the inner or outer surface of a bent part are considered. The scattering behaviors of Lamb waves in the bent plate with or without a crack are discussed in order to investigate the potential of Lamb wave ultrasonic method for characterizing cracks in a bent part. Experimental study is also carried out to verify the numerical results.

Characterization of Lamb wave attenuation mechanisms

2013 ◽  
Author(s):  
Daniel Schmidt ◽  
Hossein Sadri ◽  
Artur Szewieczek ◽  
Michael Sinapius ◽  
Peter Wierach ◽  
...  
Keyword(s):  
Lamb Wave ◽  
Wave Attenuation

A time domain spectral layerwise finite element for wave structural health monitoring in composite strips with physically modeled active piezoelectric actuators and sensors

2016 ◽  
Vol 28 (4) ◽  
pp. 488-506 ◽  
Author(s):  
Christoforos S Rekatsinas ◽  
Dimitris A Saravanos
Keyword(s):  
Finite Element ◽  
Time Domain ◽  
Lamb Wave ◽  
Lamb Waves ◽  
Piezoelectric Actuators ◽  
Numerical Results ◽  
Integration Scheme ◽  
Element Formulation ◽  
Spectral Finite Element ◽  
Piezoelectric Actuators And Sensors

A new explicit, two-dimensional plane strain, time domain spectral finite element is developed to enhance the simulation of guided waves generated by active piezoelectric sensors in laminated composite strips. A new multi-field layerwise theory is formulated for composite laminates with piezoelectric actuators and sensors which captures straight-crested symmetric and anti-symmetric Lamb waves. Third-order Hermite polynomial splines are employed for the approximation of displacements and electric potential through the thickness, and the piezoelectric actuators and sensors are physically modeled through coupled electromechanical governing equations. A multi-node finite element formulation is presented entailing displacement and electric degrees of freedom at nodes collocated with Gauss–Lobatto–Legendre integration points. Stiffness, diagonal mass, piezoelectric, and electric permittivity matrices are described, and the coupled transient electromechanical response is predicted by a properly formulated explicit time integration scheme. The numerical results of a nine-node time domain spectral finite element are correlated with the reported numerical results and with measured Lamb wave data generated by piezoceramic active sensor pairs in carbon/epoxy plate strips. Important effects introduced by the stiffness and mass of the active actuator/sensor system on Lamb wave propagation are captured by the developed finite element and quantified.

Lamb Wave Tomography and Its Application in Pipe Erosion/Corrosion Monitoring

1996 ◽  
Vol 8 (1) ◽  
pp. 189-197
Author(s):  
J. Pei ◽  
M. I. Yousuf ◽  
F. L. Degertekin ◽  
B. V. Honein ◽  
B. T. Khuri-Yakub
Keyword(s):  
Lamb Wave ◽  
Corrosion Monitoring ◽  
Erosion Corrosion ◽  
Wave Tomography

THE ANALYSIS OF ULTRASONIC WAVE ATTENUATION SPECTRA IN STEELS

1983 ◽  
Vol 44 (C9) ◽  
pp. C9-337-C9-340 ◽  
Author(s):  
R. L. Smith ◽  
W. N. Reynolds ◽  
S. Perring
Keyword(s):  
Ultrasonic Wave ◽  
Wave Attenuation

Bulk drag coefficient of a subaquatic vegetation subjected to irregular waves: Influence of Reynolds and Keulegan-Carpenter numbers

2020 ◽  
pp. 34-42
Author(s):  
Thibault Chastel ◽  
Kevin Botten ◽  
Nathalie Durand ◽  
Nicole Goutal
Keyword(s):  
Drag Coefficient ◽  
Wave Height ◽  
Wave Attenuation ◽  
Empirical Relationship ◽  
Breaking Waves ◽  
Irregular Waves ◽  
Geometrical Parameters ◽  
Flume Experiments ◽  
Seagrass Meadows ◽  
Artificial Vegetation

Seagrass meadows are essential for protection of coastal erosion by damping wave and stabilizing the seabed. Seagrass are considered as a source of water resistance which modifies strongly the wave dynamics. As a part of EDF R & D seagrass restoration project in the Berre lagoon, we quantify the wave attenuation due to artificial vegetation distributed in a flume. Experiments have been conducted at Saint-Venant Hydraulics Laboratory wave flume (Chatou, France). We measure the wave damping with 13 resistive waves gauges along a distance L = 22.5 m for the “low” density and L = 12.15 m for the “high” density of vegetation mimics. A JONSWAP spectrum is used for the generation of irregular waves with significant wave height Hs ranging from 0.10 to 0.23 m and peak period Tp ranging from 1 to 3 s. Artificial vegetation is a model of Posidonia oceanica seagrass species represented by slightly flexible polypropylene shoots with 8 artificial leaves of 0.28 and 0.16 m height. Different hydrodynamics conditions (Hs, Tp, water depth hw) and geometrical parameters (submergence ratio α, shoot density N) have been tested to see their influence on wave attenuation. For a high submergence ratio (typically 0.7), the wave attenuation can reach 67% of the incident wave height whereas for a low submergence ratio (< 0.2) the wave attenuation is negligible. From each experiment, a bulk drag coefficient has been extracted following the energy dissipation model for irregular non-breaking waves developed by Mendez and Losada (2004). This model, based on the assumption that the energy loss over the species meadow is essentially due to the drag force, takes into account both wave and vegetation parameter. Finally, we found an empirical relationship for Cd depending on 2 dimensionless parameters: the Reynolds and Keulegan-Carpenter numbers. These relationships are compared with other similar studies.

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