B. Castagnede - Academia.edu (original) (raw)

Papers by B. Castagnede

The Note describes some measurements of reflection coefficient versus incidence angle for acousti... more The Note describes some measurements of reflection coefficient versus incidence angle for acoustic materials immersed in air. This work has been performed using a low frequency (39 kHz) ultrasonic reflecto-refractometer having two independent goniometers. The amplitude measurements were performed on the specular reflection in the Fourier domain with fast algorithms involving the power spectrum. The experimental results are compared with some available theoretical models. An acceptable agreement is observed when the anisotropy of the tortuosity coefficient is taken into account

Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics-Physics-Astronomy, 1998

ABSTRACT The present note discusses the dispersion that occurs in sediments saturated by water at... more ABSTRACT The present note discusses the dispersion that occurs in sediments saturated by water at medium ultrasonic frequencies (in the 0.2–1.2 MHz range). A standard algorithm based on the phase spectrum is used to calculate the phase velocity versus frequency. Some measurements have been performed on a granular material (a sand sample provided by IFREMER). It is shown that the wavespeed decreases slightly versus frequency. The implications of such measurements are discussed in relation with theoretical models and some recently published results.RésuméLa présente note discute la dispersion qui se produit dans des sédiments saturés d'eau à l'aide d'ultrasons de moyennes fréquences (dans la gamme 0,2–1,2 MHz). Un algorithme classique mettant en œuvre le spectre de phase est utilisé pour calculer la vitesse de phase en fonction de la fréquence. Des mesures sont réalisées pour un matériau granulaire (un échantillon de sable fourni par l'IFREMER). Il est montré que la vitesse décroît légèrement avec la fréquence. L'implication de ces mesures est discutée en relation avec les modèles théoriques et des résultats récents de la littérature.

Comptes Rendus De L Academie Des Sciences Serie 2 Mecanique Physique Chimie Sciences De L Univers Sciences De La Terre, 1990

Under the action of a very intense white beam of pulsed X-rays, glass plates are seriously damage... more Under the action of a very intense white beam of pulsed X-rays, glass plates are seriously damaged. Cracks formed from pre-existent scratches, ultimately leading to catastrophic failure of the sample. Some characteristic transients of acoustic emission events are recorded

NDT & E International, 1994

Abstract This article sets out to review the methods that are available for determining the elast... more Abstract This article sets out to review the methods that are available for determining the elastic constants of anisotropic solids, with particular emphasis on techniques that involve the measurement of bulk acoustic wavespeeds. Some of the comparative advantages and disadvantages of the various methods are pointed out. In describing ultrasonic wave transmission, attention is given to the question of whether it is the phase or group velocity that is measured. Finally, the algorithms used for obtaining elastic constants from bulk acoustic wave phase and group velocity data are discussed.

Granular materials are widely used in different brunches of industry from the building constructi... more Granular materials are widely used in different brunches of industry from the building construction to pharmaceutical and production of the nanostructured materials. Classical acoustical methods for their diagnostics are well known to be very useful. By the present communication we would like to attract the attention to the possible applications of the emerging nonlinear acoustical methods for the nondestructive evaluation of the granular materials. Three potential applications are discussed. First, due to high nonlinearity of the granular materials the parametric emitting antenna can operate with sufficient efficiency in these materials. Thus, similar to the advantages achieved in underwater applications of the parametric sonar, compact sources of highly directive low-frequency sound waves can be created for the acoustic spectroscopy, tomography and depth-profiling of the granular piles and columns. Second, due to high sensitivity of the nonlinear phenomena to the state of the inter-grain contacts, such processes involving polarized shear waves are sensitive to the force chains network through its anisotropy when a uniaxial static stress is applied on the medium. Finally, few results related to a recently developed model describing the parametric antenna operation in a uni-dimensional chain of identical elastic beads are discussed. Discrete feature of the lattice and evanescent modes are taken into account.

Journal of Applied Physics, 1990

Optimal determination of the elastic constants of composite materials from ultrasonic wave‐speed ... more Optimal determination of the elastic constants of composite materials from ultrasonic wave‐speed measurements. [Journal of Applied Physics 67, 2753 (1990)]. Bernard Castagnède, James T. Jenkins, Wolfgang Sachse, Stéphane Baste. Abstract. ...

Time-domain Brillouin scattering technique, also known as picosecond ultrasonic interferometry, w... more Time-domain Brillouin scattering technique, also known as picosecond ultrasonic interferometry, which provides opportunity to monitor propagation of nanometers to sub-micrometers length coherent acoustic pulses in the samples of submicrometers to tens of micrometers dimensions, was applied to depth-profiling of polycrystalline aggregate of ice compressed in a diamond anvil cell to Megabar pressures. The technique allowed examination of characteristic dimensions of elastic inhomogeneities and texturing of polycrystalline ice in the direction normal to the diamond anvil surfaces with sub-micrometer spatial resolution via time-resolved measurements of variations in the propagation velocity of the acoustic pulse traveling in the compressed sample. The achieved two-dimensional imaging of the polycrystalline ice aggregate in-depth and in one of the lateral directions indicates the feasibility of three-dimensional imaging and quantitative characterization of acoustical, optical and acousto-optical properties of transparent polycrystalline aggregates in diamond anvil cell with tens of nanometers in-depth resolution and lateral spatial resolution controlled by pump laser pulses focusing.

Publications Du Lma, 1996

La propagation du son dans les materiaux poreux satures par un fluide leger est assez bien decrit... more La propagation du son dans les materiaux poreux satures par un fluide leger est assez bien decrite par une theorie a une onde (D. Lafarge, GDR vibroacoustique, mars 1996). Celle-ci s'applique au cas ou le squelette solide est suppose rigide, ce qui est verifie experimentalement lorsque la frequence est superieure a quelques 10 2 Hz. Aux frequences ultrasonores, il est possible d'effectuer des developpements asymptotiques qui permettent d'exprimer le coefficient de compressibilite, et la masse volumique effective sous des formes simples directement exploitables. Les techniques ultrasonores BF apparaissent comme des complements utiles aux methodes de caracterisation dans la gamme audio (20 Hz - 20 kHz). Des confrontations theorie / experience sont decrites pour diverses configurations sur plusieurs materiaux poreux satures d'air. Les travaux experimentaux utilisent un reflecto - refractometre ultrasonore permettant de mesurer les coefficients de reflexion, ou de transmission. Des resultats significatifs ayant trait a l'anisotropie et a l'heterogeneite de certains parametres constitutifs (tel que la tortuosite) sont presentes, ainsi que des travaux recents concemant la determination des longueurs caracteristiques visqueuse et thermique par des techniques ultrasonores.

A thermoelastic mechanism that manifests itself as nonlinear dissipation of acoustic waves withou... more A thermoelastic mechanism that manifests itself as nonlinear dissipation of acoustic waves without implying either hysteresis or nonlinear viscous-like losses is considered. This idea was earlier considered at rheological level by the present authors for microinhomogeneous solids with defects possessing elastic nonlinearity and linear viscous-like dissipation. In the present paper, this mechanism is discussed first from a more general point of view in terms of relaxators with parameters varied due to purely reactive nonlinearity. Then it is considered in details for a practically important special case of such relaxators in the form of cracks containing inner contacts. It is shown that, due to strong stress concentration at the contacts and due to enhanced temperature gradients, the thermoelastic dissipation at these relaxators can be very efficient. Implications for linear small-amplitude losses as well as nonlinear effects of induced transparency and induced dissipation are discussed. The two latter effects may coexist and be observed at different frequency ranges (below and above the relaxation maximum). The considered amplitude-dependent effects are typical of the same defects that may also exhibit hysteretic properties due to adhesion or friction mechanisms. Thus the discussed non-hysteretic and hysteretic mechanisms may be activated simultaneously, which should be taken into account in theoretical interpretation of observations.

Acoustical Physics, 2005

The interrelated elastic and inelastic fast and slow effects of acoustic wave interaction with cr... more The interrelated elastic and inelastic fast and slow effects of acoustic wave interaction with cracks are discussed from a unified point of view. Special attention is given to the dissipative manifestations of the presence of cracks and to the effects of the symmetrically time-reversible slow dynamics observed for acoustically activated cracks. These effects can be more pronounced than the conventionally discussed nonlinear elastic effects (such as higher harmonic generation). Taking into account the main geometric features of cracks, a thermoelastic mechanism is proposed to consistently interpret the experimental data. Consequences of the results of these studies for seismics are discussed, and the possibilities of using the observed effects for nonlinear acoustic diagnostics of cracks are discussed.

In relation to the growing interest to the defectoscopy technique of damaged materials by nonline... more In relation to the growing interest to the defectoscopy technique of damaged materials by nonlinear ultrasonic methods, a new approach is described. Based upon increased nonlinearity of the material due to the presence of cracks, strong interaction between independent ultrasonic waves is possible. Modulation transfer is one of the forms of this interaction. In the present work an amplitudemodulated pump wave, at a few Hertz, has been used to induce variations of the main mechanical parameters of the material. These parameters have been tested by a probe wave of smaller amplitude. Thus, the amplitude of the probe wave is influenced by the variation of the material parameters under the action of the pump, synchronously with pump amplitude. Significant variations have been observed on the tested plates in terms of their Frequency Response Functions with and without pump (no modulation). The correlation between those variations and depth of induced amplitude modulation of the probe has ...

On discute des resultats obtenus par plusieurs methodes pour les constantes elastiques hors du pl... more On discute des resultats obtenus par plusieurs methodes pour les constantes elastiques hors du plan du papier. On compare les methodes mecanique et acoustique, la methode acoustique donnant en general les meilleurs resultats

An experimental study of a Duffing-type oscillator having a geometrical non-linearity is presente... more An experimental study of a Duffing-type oscillator having a geometrical non-linearity is presented. The experimental results exhibit every classical characteristic of a non-linear oscillator which is modelised by the asymptotic theory. These are: 1. Second order transition in the resonance curve with hysteresis loop. 2. Anharmonicity factor related to the shift of the resonance frequency versus sollicitation amplitude. 3. Critical amplitude. Predictions from the theoretical model of some constitutive parameters of the mechanical system are in agreement with the experimental results L'etude experimentale d'un oscillateur du type Duffing possedant une non-linearite geometrique est presentee. Les resultats experimentaux font apparaitre toutes les caracteristiques classiques d'un oscillateur non lineaire modelise par la theorie asymptotique, a savoir: 1. Transition du deuxieme ordre dans la courbe de resonance avec boucle d'hysteresis; 2. Facteur d'anharmonicite rela...

The three bulk modes are generally identified at the epicentre configuration. The quasi-longitudi... more The three bulk modes are generally identified at the epicentre configuration. The quasi-longitudinal mode is tracked by using a correlation algorithm, during scanning experiments along principal acoustic axes, up to a large observation angle (typically in the range of 80°). The two transverse modes are more difficult, for several reasons, to obtain with precision. The wavespeeds obtained by using the laser technique are compared with traditional ultrasonic data for two different composite materials

Due to their dimensionless character, Poisson ratios are fundamental quantities of linear elastic... more Due to their dimensionless character, Poisson ratios are fundamental quantities of linear elasticity. When dealing with isotropic solids, a simple analytical expression relates the Poisson ratio to longitudinal and shear wavespeeds. Using the shift, the real signification of these coefficients is discussed Pour les solides isotropes, une relation analytique simple relie le coefficient de Poisson aux celerites des ondes longitudinales et de cisaillement. On discute par ce biais de la signification profonde de ces coefficients

... Auteur(s) / Author(s). CASTAGNEDE B. (1) ; MARK RE ; SEO YB ; ... On analyse ces divergences ... more ... Auteur(s) / Author(s). CASTAGNEDE B. (1) ; MARK RE ; SEO YB ; ... On analyse ces divergences en insistant sur les implications physiques de ces techniques sp??cifiques et sur le d??veloppement d'un crit??re orthotropique que l'on appelle ??jauge anisotrope?? Revue / Journal Title. ...

An optimization process is presented for locating an acoustic emission source which is supposed t... more An optimization process is presented for locating an acoustic emission source which is supposed to be point-like in a homogeneous anisotropic material. The solution of the two-dimensional specific problem for a plate with parallel surfaces yields a non-linear system of transcendental equations which is numerically solved by an iterative scheme. Some results obtained in simulation showing the robustness of the algorithm are discussed La resolution du probleme specifique a 2 dimensions pour une lame a faces paralleles aboutit a un systeme non lineaire d'equations transcendantes qui est numeriquement traite par approximations successives

The Note describes some measurements of reflection coefficient versus incidence angle for acousti... more The Note describes some measurements of reflection coefficient versus incidence angle for acoustic materials immersed in air. This work has been performed using a low frequency (39 kHz) ultrasonic reflecto-refractometer having two independent goniometers. The amplitude measurements were performed on the specular reflection in the Fourier domain with fast algorithms involving the power spectrum. The experimental results are compared with some available theoretical models. An acceptable agreement is observed when the anisotropy of the tortuosity coefficient is taken into account

Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics-Physics-Astronomy, 1998

ABSTRACT The present note discusses the dispersion that occurs in sediments saturated by water at... more ABSTRACT The present note discusses the dispersion that occurs in sediments saturated by water at medium ultrasonic frequencies (in the 0.2–1.2 MHz range). A standard algorithm based on the phase spectrum is used to calculate the phase velocity versus frequency. Some measurements have been performed on a granular material (a sand sample provided by IFREMER). It is shown that the wavespeed decreases slightly versus frequency. The implications of such measurements are discussed in relation with theoretical models and some recently published results.RésuméLa présente note discute la dispersion qui se produit dans des sédiments saturés d'eau à l'aide d'ultrasons de moyennes fréquences (dans la gamme 0,2–1,2 MHz). Un algorithme classique mettant en œuvre le spectre de phase est utilisé pour calculer la vitesse de phase en fonction de la fréquence. Des mesures sont réalisées pour un matériau granulaire (un échantillon de sable fourni par l'IFREMER). Il est montré que la vitesse décroît légèrement avec la fréquence. L'implication de ces mesures est discutée en relation avec les modèles théoriques et des résultats récents de la littérature.

Comptes Rendus De L Academie Des Sciences Serie 2 Mecanique Physique Chimie Sciences De L Univers Sciences De La Terre, 1990

Under the action of a very intense white beam of pulsed X-rays, glass plates are seriously damage... more Under the action of a very intense white beam of pulsed X-rays, glass plates are seriously damaged. Cracks formed from pre-existent scratches, ultimately leading to catastrophic failure of the sample. Some characteristic transients of acoustic emission events are recorded

NDT & E International, 1994

Abstract This article sets out to review the methods that are available for determining the elast... more Abstract This article sets out to review the methods that are available for determining the elastic constants of anisotropic solids, with particular emphasis on techniques that involve the measurement of bulk acoustic wavespeeds. Some of the comparative advantages and disadvantages of the various methods are pointed out. In describing ultrasonic wave transmission, attention is given to the question of whether it is the phase or group velocity that is measured. Finally, the algorithms used for obtaining elastic constants from bulk acoustic wave phase and group velocity data are discussed.

Granular materials are widely used in different brunches of industry from the building constructi... more Granular materials are widely used in different brunches of industry from the building construction to pharmaceutical and production of the nanostructured materials. Classical acoustical methods for their diagnostics are well known to be very useful. By the present communication we would like to attract the attention to the possible applications of the emerging nonlinear acoustical methods for the nondestructive evaluation of the granular materials. Three potential applications are discussed. First, due to high nonlinearity of the granular materials the parametric emitting antenna can operate with sufficient efficiency in these materials. Thus, similar to the advantages achieved in underwater applications of the parametric sonar, compact sources of highly directive low-frequency sound waves can be created for the acoustic spectroscopy, tomography and depth-profiling of the granular piles and columns. Second, due to high sensitivity of the nonlinear phenomena to the state of the inter-grain contacts, such processes involving polarized shear waves are sensitive to the force chains network through its anisotropy when a uniaxial static stress is applied on the medium. Finally, few results related to a recently developed model describing the parametric antenna operation in a uni-dimensional chain of identical elastic beads are discussed. Discrete feature of the lattice and evanescent modes are taken into account.

Journal of Applied Physics, 1990

Optimal determination of the elastic constants of composite materials from ultrasonic wave‐speed ... more Optimal determination of the elastic constants of composite materials from ultrasonic wave‐speed measurements. [Journal of Applied Physics 67, 2753 (1990)]. Bernard Castagnède, James T. Jenkins, Wolfgang Sachse, Stéphane Baste. Abstract. ...

Time-domain Brillouin scattering technique, also known as picosecond ultrasonic interferometry, w... more Time-domain Brillouin scattering technique, also known as picosecond ultrasonic interferometry, which provides opportunity to monitor propagation of nanometers to sub-micrometers length coherent acoustic pulses in the samples of submicrometers to tens of micrometers dimensions, was applied to depth-profiling of polycrystalline aggregate of ice compressed in a diamond anvil cell to Megabar pressures. The technique allowed examination of characteristic dimensions of elastic inhomogeneities and texturing of polycrystalline ice in the direction normal to the diamond anvil surfaces with sub-micrometer spatial resolution via time-resolved measurements of variations in the propagation velocity of the acoustic pulse traveling in the compressed sample. The achieved two-dimensional imaging of the polycrystalline ice aggregate in-depth and in one of the lateral directions indicates the feasibility of three-dimensional imaging and quantitative characterization of acoustical, optical and acousto-optical properties of transparent polycrystalline aggregates in diamond anvil cell with tens of nanometers in-depth resolution and lateral spatial resolution controlled by pump laser pulses focusing.

Publications Du Lma, 1996

La propagation du son dans les materiaux poreux satures par un fluide leger est assez bien decrit... more La propagation du son dans les materiaux poreux satures par un fluide leger est assez bien decrite par une theorie a une onde (D. Lafarge, GDR vibroacoustique, mars 1996). Celle-ci s'applique au cas ou le squelette solide est suppose rigide, ce qui est verifie experimentalement lorsque la frequence est superieure a quelques 10 2 Hz. Aux frequences ultrasonores, il est possible d'effectuer des developpements asymptotiques qui permettent d'exprimer le coefficient de compressibilite, et la masse volumique effective sous des formes simples directement exploitables. Les techniques ultrasonores BF apparaissent comme des complements utiles aux methodes de caracterisation dans la gamme audio (20 Hz - 20 kHz). Des confrontations theorie / experience sont decrites pour diverses configurations sur plusieurs materiaux poreux satures d'air. Les travaux experimentaux utilisent un reflecto - refractometre ultrasonore permettant de mesurer les coefficients de reflexion, ou de transmission. Des resultats significatifs ayant trait a l'anisotropie et a l'heterogeneite de certains parametres constitutifs (tel que la tortuosite) sont presentes, ainsi que des travaux recents concemant la determination des longueurs caracteristiques visqueuse et thermique par des techniques ultrasonores.

A thermoelastic mechanism that manifests itself as nonlinear dissipation of acoustic waves withou... more A thermoelastic mechanism that manifests itself as nonlinear dissipation of acoustic waves without implying either hysteresis or nonlinear viscous-like losses is considered. This idea was earlier considered at rheological level by the present authors for microinhomogeneous solids with defects possessing elastic nonlinearity and linear viscous-like dissipation. In the present paper, this mechanism is discussed first from a more general point of view in terms of relaxators with parameters varied due to purely reactive nonlinearity. Then it is considered in details for a practically important special case of such relaxators in the form of cracks containing inner contacts. It is shown that, due to strong stress concentration at the contacts and due to enhanced temperature gradients, the thermoelastic dissipation at these relaxators can be very efficient. Implications for linear small-amplitude losses as well as nonlinear effects of induced transparency and induced dissipation are discussed. The two latter effects may coexist and be observed at different frequency ranges (below and above the relaxation maximum). The considered amplitude-dependent effects are typical of the same defects that may also exhibit hysteretic properties due to adhesion or friction mechanisms. Thus the discussed non-hysteretic and hysteretic mechanisms may be activated simultaneously, which should be taken into account in theoretical interpretation of observations.

Acoustical Physics, 2005

The interrelated elastic and inelastic fast and slow effects of acoustic wave interaction with cr... more The interrelated elastic and inelastic fast and slow effects of acoustic wave interaction with cracks are discussed from a unified point of view. Special attention is given to the dissipative manifestations of the presence of cracks and to the effects of the symmetrically time-reversible slow dynamics observed for acoustically activated cracks. These effects can be more pronounced than the conventionally discussed nonlinear elastic effects (such as higher harmonic generation). Taking into account the main geometric features of cracks, a thermoelastic mechanism is proposed to consistently interpret the experimental data. Consequences of the results of these studies for seismics are discussed, and the possibilities of using the observed effects for nonlinear acoustic diagnostics of cracks are discussed.

In relation to the growing interest to the defectoscopy technique of damaged materials by nonline... more In relation to the growing interest to the defectoscopy technique of damaged materials by nonlinear ultrasonic methods, a new approach is described. Based upon increased nonlinearity of the material due to the presence of cracks, strong interaction between independent ultrasonic waves is possible. Modulation transfer is one of the forms of this interaction. In the present work an amplitudemodulated pump wave, at a few Hertz, has been used to induce variations of the main mechanical parameters of the material. These parameters have been tested by a probe wave of smaller amplitude. Thus, the amplitude of the probe wave is influenced by the variation of the material parameters under the action of the pump, synchronously with pump amplitude. Significant variations have been observed on the tested plates in terms of their Frequency Response Functions with and without pump (no modulation). The correlation between those variations and depth of induced amplitude modulation of the probe has ...

On discute des resultats obtenus par plusieurs methodes pour les constantes elastiques hors du pl... more On discute des resultats obtenus par plusieurs methodes pour les constantes elastiques hors du plan du papier. On compare les methodes mecanique et acoustique, la methode acoustique donnant en general les meilleurs resultats

An experimental study of a Duffing-type oscillator having a geometrical non-linearity is presente... more An experimental study of a Duffing-type oscillator having a geometrical non-linearity is presented. The experimental results exhibit every classical characteristic of a non-linear oscillator which is modelised by the asymptotic theory. These are: 1. Second order transition in the resonance curve with hysteresis loop. 2. Anharmonicity factor related to the shift of the resonance frequency versus sollicitation amplitude. 3. Critical amplitude. Predictions from the theoretical model of some constitutive parameters of the mechanical system are in agreement with the experimental results L'etude experimentale d'un oscillateur du type Duffing possedant une non-linearite geometrique est presentee. Les resultats experimentaux font apparaitre toutes les caracteristiques classiques d'un oscillateur non lineaire modelise par la theorie asymptotique, a savoir: 1. Transition du deuxieme ordre dans la courbe de resonance avec boucle d'hysteresis; 2. Facteur d'anharmonicite rela...

The three bulk modes are generally identified at the epicentre configuration. The quasi-longitudi... more The three bulk modes are generally identified at the epicentre configuration. The quasi-longitudinal mode is tracked by using a correlation algorithm, during scanning experiments along principal acoustic axes, up to a large observation angle (typically in the range of 80°). The two transverse modes are more difficult, for several reasons, to obtain with precision. The wavespeeds obtained by using the laser technique are compared with traditional ultrasonic data for two different composite materials

Due to their dimensionless character, Poisson ratios are fundamental quantities of linear elastic... more Due to their dimensionless character, Poisson ratios are fundamental quantities of linear elasticity. When dealing with isotropic solids, a simple analytical expression relates the Poisson ratio to longitudinal and shear wavespeeds. Using the shift, the real signification of these coefficients is discussed Pour les solides isotropes, une relation analytique simple relie le coefficient de Poisson aux celerites des ondes longitudinales et de cisaillement. On discute par ce biais de la signification profonde de ces coefficients

... Auteur(s) / Author(s). CASTAGNEDE B. (1) ; MARK RE ; SEO YB ; ... On analyse ces divergences ... more ... Auteur(s) / Author(s). CASTAGNEDE B. (1) ; MARK RE ; SEO YB ; ... On analyse ces divergences en insistant sur les implications physiques de ces techniques sp??cifiques et sur le d??veloppement d'un crit??re orthotropique que l'on appelle ??jauge anisotrope?? Revue / Journal Title. ...

An optimization process is presented for locating an acoustic emission source which is supposed t... more An optimization process is presented for locating an acoustic emission source which is supposed to be point-like in a homogeneous anisotropic material. The solution of the two-dimensional specific problem for a plate with parallel surfaces yields a non-linear system of transcendental equations which is numerically solved by an iterative scheme. Some results obtained in simulation showing the robustness of the algorithm are discussed La resolution du probleme specifique a 2 dimensions pour une lame a faces paralleles aboutit a un systeme non lineaire d'equations transcendantes qui est numeriquement traite par approximations successives