Finite element predictions for the dynamic response of thermo-viscoelastic material structures

Castaings, Michel; Bacon, C.; Hosten, Bernard; Predoi, Mihai Valentin

doi:10.1121/1.1639332

Cited by 83 publications

(51 citation statements)

References 22 publications

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“…Absorbing regions of length 0.8 m were included on both sides of the 2m wide aluminium plate, to avoid standing wave modes and to allow proper representation of radiating leaking waves if present. As described in reports of previous work with absorbing regions [23,24], the absorbing region had the same mass density and elastic properties as the medium of interest, but its viscoelastic coefficient gradually increased with the distance away from the region of interest. Continuity of displacements and stresses was imposed at the internal borders between the stiffener, the adhesive layer and the aluminium plate.…”

Section: Safe Modellingmentioning

confidence: 77%

Feature-guided waves for monitoring adhesive shear modulus in bonded stiffeners

Fan

Castaings

Lowe

et al. 2013

NDT & E International

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Adhesively bonded stiffeners are employed in aerospace applications to increase structural stiffness. The potential of feature-guided wave modes for the verification of adhesion and curing state in difficult-to-access regions has been investigated. The properties of guided wave modes propagating along a T-shaped stiffener bonded to an aluminium plate were calculated using the Semi-Analytical Finite Element (SAFE) method. Feature-guided modes dominated by shearing motion were identified to be well suited, with energy concentrated at the stiffener and bond line, limiting energy radiation into the plate and thus maximising inspection length. The influences of the bond line stiffness and thickness on the guided wave behaviour were investigated using SAFE and 3D Finite Element calculations, and found to be significant. Experiments were conducted to measure the properties of the guided waves during the curing of an epoxy joint attaching a stiffener to a plate. The feature-guided mode was excited using a piezo-electric shear transducer and measured using a laser interferometer. The measured phase speed changed significantly during curing. The frequency dependency was found to match well with the SAFE calculations for a variation of the shear (Coulomb) modulus of the adhesive. The potential of the featureguided shear wave mode for bond line inspection and monitoring has been shown and the choice of guided wave mode and frequency range for good sensitivity to the bond line state discussed.

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Section: Safe Modellingmentioning

confidence: 77%

Feature-guided waves for monitoring adhesive shear modulus in bonded stiffeners

Fan

Castaings

Lowe

et al. 2013

NDT & E International

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“…Moreover, the attenuation was measured by reproducing the EPJ Web of Conferences 170, 03005 (2018) https://doi.org/10.1051/epjconf/201817003005 ANIMMA 2017 2D Fourier transform twice in two different propagation zones. This technique is presented in [17], but is applied now to measure the leaky attenuation and not anymore the attenuation of composite material. In the literature, group velocity are generally measured by measuring the speed of the envelope [14], [18].…”

Section: Experimentation In Water and Data Processingmentioning

confidence: 99%

Study of Lamb Waves for Non-Destructive Testing Behind Screens

et al. 2018

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Abstract-The inspection and control of sodium-cooled fast reactors (SFR) is a major issue for the nuclear industry. Ultrasonic solutions are under study because of the opacity of liquid sodium. In this paper, the use of leaky Lamb waves is considered for non-destructive testing (NDT) on parallel and immersed structures assimilated as plates. The first phase of our approach involved studying the propagation properties of leaky Lamb waves. Equations that model the propagation of Lamb waves in an immersed plate were solved numerically. The phase velocity can be experimentally measured using a two dimensional Fourier transform. The group velocity can be experimentally measured using a short-time Fourier transform technique. Attenuation of leaky Lamb waves is mostly due to the re-emission of energy into the surrounding fluid, and it can be measured by these two techniques.

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“…The model was solved in the frequency domain using a frequency-dependent mesh and absorbing region. 16 The time domain response was obtained from the inverse discrete Fourier transform of the frequency domain response.…”

Section: Numerical Modelingmentioning

confidence: 99%

Poisson's ratio from polarization of acoustic zero-group velocity Lamb mode

Baggens

Rydén

2015

The Journal of the Acoustical Society of America

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Poisson's ratio of an isotropic and free elastic plate is estimated from the polarization of the first symmetric acoustic zero-group velocity Lamb mode. This polarization is interpreted as the ratio of the absolute amplitudes of the surface normal and surface in-plane components of the acoustic mode. Results from the evaluation of simulated datasets indicate that the presented relation, which links the polarization and Poisson's ratio, can be extended to incorporate plates with material damping. Furthermore, the proposed application of the polarization is demonstrated in a practical field case, where an increased accuracy of estimated nominal thickness is obtained.

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Finite element predictions for the dynamic response of thermo-viscoelastic material structures

Cited by 83 publications

References 22 publications

Feature-guided waves for monitoring adhesive shear modulus in bonded stiffeners

Feature-guided waves for monitoring adhesive shear modulus in bonded stiffeners

Study of Lamb Waves for Non-Destructive Testing Behind Screens

Poisson's ratio from polarization of acoustic zero-group velocity Lamb mode

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