scholarly journals Analysis of Rayleigh-Lamb wave scattering by a crack in an elastic plate

1997 ◽  
Vol 19 (6) ◽  
pp. 533-537 ◽  
Author(s):  
L. J. Crane ◽  
M. D. Gilchrist ◽  
J. J. H. Miller
Keyword(s):  
Elastic Plate ◽  
Lamb Wave ◽  
Wave Scattering

scholarly journals Lamb Wave Scattering Analysis for Interface Damage Detection between a Surface-Mounted Block and Elastic Plate

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 860
Author(s):  
Mikhail V. Golub ◽  
Alisa N. Shpak ◽  
Inka Mueller ◽  
Sergey I. Fomenko ◽  
Claus-Peter Fritzen
Keyword(s):  
Damage Detection ◽  
Elastic Plate ◽  
Lamb Wave ◽  
Wave Scattering ◽  
Hybrid Approach ◽  
Guided Wave ◽  
Open Crack ◽  
Damage Indices ◽  
Impulse Function ◽  
Thin Walled

Since stringers are often applied in engineering constructions to improve thin-walled structures’ strength, methods for damage detection at the joints between the stringer and the thin-walled structure are necessary. A 2D mathematical model was employed to simulate Lamb wave excitation and sensing via rectangular piezoelectric-wafer active transducers mounted on the surface of an elastic plate with rectangular surface-bonded obstacles (stiffeners) with interface defects. The results of a 2D simulation using the finite element method and the semi-analytical hybrid approach were validated experimentally using laser Doppler vibrometry for fully bonded and semi-debonded rectangular obstacles. A numerical analysis of fundamental Lamb wave scattering via rectangular stiffeners in different bonding states is presented. Two kinds of interfacial defects between the stiffener and the plate are considered: the partial degradation of the adhesive at the interface and an open crack. Damage indices calculated using the data obtained from a sensor are analyzed numerically. The choice of an input impulse function applied at the piezoelectric actuator is discussed from the perspective of the development of guided-wave-based structural health monitoring techniques for damage detection.

Wave Propagation in a Micropolar Elastic Plate with Voids

2005 ◽  
Vol 11 (6) ◽  
pp. 849-863 ◽  
Author(s):  
S. K. Tomar
Keyword(s):  
Wave Propagation ◽  
Attenuation Coefficient ◽  
Elastic Material ◽  
Elastic Plate ◽  
Lamb Wave ◽  
Specific Model ◽  
Present Formulation ◽  
Numerical Computations ◽  
Lamb Wave Propagation ◽  
Symmetric And Antisymmetric Modes

Frequency equations are obtained for Rayleigh–Lamb wave propagation in a plate of micropolar elastic material with voids. The thickness of the plate is taken to be finite and the faces of the plate are assumed to be free from stresses. The frequency equations are obtained corresponding to symmetric and antisymmetric modes of vibrations of the plate, and some limiting cases of these equations are discussed. Numerical computations are made for a specific model to solve the frequency equations for symmetric and antisymmetric modes of propagation. It is found that both modes of vibrations are dispersive and the presence of voids has a negligible effect on these dispersion curves. However, the attenuation coefficient is found to be influenced by the presence of voids. The results of some earlier works are also deduced from the present formulation.

Prediction and Measurement of Lamb Wave from Debondings at Structural Features in Composite Laminates

2013 ◽  
Vol 558 ◽  
pp. 139-148 ◽  
Author(s):  
Ching Tai Ng ◽  
Martin Veidt
Keyword(s):  
Lamb Wave ◽  
Composite Laminates ◽  
Wave Scattering ◽  
Three Dimensional ◽  
Scattered Wave ◽  
Structural Features ◽  
Complex Structures ◽  
Detection Techniques ◽  
Fe Simulations ◽  
Good Agreement

The interaction of the fundamental anti-symmetric Lamb wave (A0) with debondings at structural features is investigated using experimental data and finite element (FE) simulations. In this study explicit three-dimensional (3D) FE simulations are employed, which allows the study of the scattered wave along different propagation directions. Good agreement between the FE predictions and the measurements are obtained that demonstrates that the 3D FE scattering model is able to accurately predict the Lamb wave scattering characteristics at debondings. The study show that the characteristics of Lamb wave reflected from the debondings at the structure feature is much more complicated than that from defects in flat composite laminates. Parameter studies show that the backward and forward scattering coefficient of Lamb wave is a function of debonding size to wavelength ratio and debonding location. This shows the potential of employing Lamb wave to identify the size and monitor the growth of the debondings. The findings of the study provide improved physical insights into the scattering phenomena, which are important to further advance damage detection techniques for complex structures made by composite laminates.

scholarly journals On Accuracy of Analytical Modeling of Lamb Wave Scattering at Delaminations in Multilayered Isotropic Plates

2015 ◽  
Vol 15 (08) ◽  
pp. 1540010 ◽  
Author(s):  
C. T. Ng
Keyword(s):  
Analytical Solutions ◽  
Lamb Wave ◽  
Wave Scattering ◽  
Plate Theory ◽  
Analytical Models ◽  
Mindlin Plate ◽  
Bending Rigidity ◽  
Scattering Problems ◽  
Explicit Finite Element ◽  
Isotropic Plates

The study investigates the accuracy of analytical solutions to the fundamental anti-symmetric Lamb wave scattering at delamination in multilayered isotropic plates. The analytical models are based on the wave function expansion method and Born approximation within the framework of Mindlin plate theory. The study validates the accuracy of modeling the delamination as an inhomogeneity with reduced bending rigidity in predicting Lamb wave scattering induced by geometry change at the delaminated region. A good agreement is observed between the analytical solutions and results of experimentally verified 3D explicit finite element (FE) simulations. The findings support the inhomogeneity assumption in Lamb wave scattering problems and show the feasibility of employing it in delamination characterization.

scholarly journals Rayleigh and Lamb wave resonances in an elastic plate

1978 ◽  
Vol 64 (S1) ◽  
pp. S129-S130
Author(s):  
R. Fiorito ◽  
W. Madigosky ◽  
H. Überall
Keyword(s):  
Elastic Plate ◽  
Lamb Wave
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