Abstract: A method for non-destructive testing of a mechanical part by a multi-element transducer having piezoelectric elements, where: for each element e(i) of the transducer, the emission of an ultrasonic wave at a given frequency and measurement, by each element e(j) distinct from the element e(i), of a time-varying signal kij(t) representing the back-scattered ultrasonic wave received by the element e(j); the determination of a first matrix of time-varying components based on measured signals kij(t), i, j=1, . . . , N; the determination of a second matrix of frequency components corresponding to a determined frequency based on the frequency of the ultrasonic wave by applying a Fourier transform to said first matrix; the filtering of said second matrix comprising a projection of it onto a single scattering sub-space determined by means of a numerical calculation using a ray tracing algorithm; and the verification of the integrity of the mechanical part by using said filtered second matrix.

Abstract: A device, for non-destructive testing of a mechanical part made of a polycrystalline material, includes: an ultrasonic probe including a two-dimensional array of transducers capable of emitting and receiving signals at different excitation angles; and a processing module suitable for controlling the emission and the reception of the transducers, for processing the signals received by the transducers so as to express the signals received by the ultrasonic probe in two planar wave planes constructed from the emission and reception wave vectors of the probe, and for deducing therefrom information representative of the three-dimensional orientation of the fiber structure of the mechanical part.

Abstract: The invention concerns a method for the non-destructive mapping of a component, in order to determine an elongation direction of the elongate microstructure of the component at at least one point of interest, characterised in that it comprises at least two successive intensity measurement steps comprising the following steps: a sub-step of rotating a linear transducer into a plurality of angular positions, said linear transducer comprising a plurality of transducer elements, a sub-step of emitting a plurality of elementary ultrasonic beams at each angular position, a sub-step of measuring a plurality of backscattered signals resulting from the backscattering of the elementary ultrasonic beams by said elongate microstructure, the intensity measurement steps making it possible to obtain two series of intensities measured according to two axes of rotation, and in that the method comprises a step of combining the measured series of intensities so as to determine the elongation direction of the microstructure at s

Abstract: This two-dimensional Fourier transform ultrasound imaging method includes by controlling transmitting and receiving transducers: obtaining M matrices MRm, 1?m?M, of sampled ultrasonic time signals; two-dimensional Fourier transforming each matrix MRm to obtain M spectral matrices FTMRm; converting each spectral matrix FTMRm to obtain M spectral images FTIm; combining the M spectral images FTIm and two-dimensional inverse Fourier transforming the resulting spectral image FTI to obtain an ultrasound image I. The conversion includes taking into account a change of propagation mode during a backscatter, by adding a parameter characterizing this change of mode in equations (SYS) of change of reference frame, and/or taking into account a reflection against a wall, by adding a phase shift term in a relation (REL) of matrix transformation.

Abstract: A method for nondestructively testing a part comprising an elongate microstructure is disclosed.

Abstract: The invention relates to a method for the non-destructive testing of a mechanical part (2) by propagation of ultrasonic waves accomplished by means of a multi-element transducer (3) placed opposite the mechanical part and comprising a plurality of piezoelectric elements e(1), e(2), . . . , e(N), N>1. It comprises: for each element e(i) of the transducer, the emission of an ultrasonic wave at a given frequency and measurement, by each element e(j) distinct from the element e(i), of a time-varying signal kij(t) representing the back-scattered ultrasonic wave received by the element e(j); the determination of a first matrix of time-varying components based on the measured signals kij(t), i,j=1, . . .

Abstract: A method for processing ultrasound signals including controlling emission transducers for M successive emissions of plane ultrasound waves having M different angles of emission, controlling N reception transducers in order to simultaneously receive N measurement time signals per emission, and obtaining a matrix [MR(t)] of ultrasound time signals, each coefficient MRi,j(t) of this matrix representing the measurement signal received by the i-th reception transducer caused by the j-th emission. It further includes performing singular-value decomposition of a matrix [FTMR(f)] of frequency signals obtained by transforming the matrix [MR(t)], and eliminating a portion of the singular values and reconstructing a denoised matrix [MRU(t)] of time signals on the basis of the singular values not eliminated.

Abstract: The invention concerns a method for the non-destructive mapping of a component, in order to determine an elongation direction of the elongate microstructure of the component at at least one point of interest, characterised in that it comprises at least two successive intensity measurement steps comprising the following steps: a sub-step of rotating a linear transducer into a plurality of angular positions, said linear transducer comprising a plurality of transducer elements, a sub-step of emitting a plurality of elementary ultrasonic beams at each angular position, a sub-step of measuring a plurality of backscattered signals resulting from the backscattering of the elementary ultrasonic beams by said elongate microstructure, the intensity measurement steps making it possible to obtain two series of intensities measured according to two axes of rotation, and in that the method comprises a step of combining the measured series of intensities so as to determine the elongation direction of the microstructure at s

Abstract: A method for acquiring signals via ultrasound probing including: controlling L emission transducers and N reception transducers in order to simultaneously receive, for each of M successive emissions, N measurement signals; obtaining a matrix of ultrasound time signals having a size of N×M. An initial matrix ([MC?]), having a size of L×M', for encoding the successive emissions is previously defined for a number M? of successive initial emissions strictly greater than M. A calculation of acoustic field is carried out for each of the M? initial emissions. A reduced encoding matrix ([MC]), having a size of L×M, is obtained by removal of M??M columns of the initial encoding matrix ([MC?]) on the basis of a selection criterion applied to the M? calculations of acoustic fields. Finally, the control of the L emission transducers for the M successive emissions is encoded using the reduced encoding matrix ([MC]).

Abstract: A method for nondestructively testing a part comprising an elongate microstructure is disclosed.

Abstract: A method for processing ultrasound signals including controlling emission transducers for M successive emissions of plane ultrasound waves having M different angles of emission, controlling N reception transducers in order to simultaneously receive N measurement time signals per emission, and obtaining a matrix [MR(t)] of ultrasound time signals, each coefficient MRi,j(t) of this matrix representing the measurement signal received by the i-th reception transducer caused by the j-th emission. It further includes performing singular-value decomposition of a matrix [FTMR(f)] of frequency signals obtained by transforming the matrix [MR(t)], and eliminating a portion of the singular values and reconstructing a denoised matrix [MRU(t)] of time signals on the basis of the singular values not eliminated.

Abstract: A method for processing ultrasonic signals includes: controlling a plurality of emission transducers for L successive emissions of ultrasonic waves; controlling N reception transducers to simultaneously receive and for a predetermined time, for each successive emission, N measurement signals; obtaining an array of ultrasonic time signals of size L×N, each coefficient Ki,j(t) of this array representing the measurement signal received by the j-th reception transducer due to the i-th emission; and denoising the time signal array by removing some of the singular values and associated singular vectors obtained from a singular value decomposition of a frequency signal array obtained by transforming this time signal array, and by reconstructing a denoised time signal array based on unremoved singular values and singular vectors.

Abstract: A method for processing ultrasonic signals includes: controlling a plurality of emission transducers for L successive emissions of ultrasonic waves; controlling N reception transducers to simultaneously receive and for a predetermined time, for each successive emission, N measurement signals; obtaining an array of ultrasonic time signals of size L×N, each coefficient Ki,j(t) of this array representing the measurement signal received by the j-th reception transducer due to the i-th emission; and denoising the time signal array by removing some of the singular values and associated singular vectors obtained from a singular value decomposition of a frequency signal array obtained by transforming this time signal array, and by reconstructing a denoised time signal array based on unremoved singular values and singular vectors.

Abstract: A laser-based ultrasonic technique for the inspection of thin plates and membranes employs an amplitude-modulated laser source to excite narrow bandwidth Lamb waves. The dominant feature in the acoustic spectrum is a sharp resonance peak that occurs at the minimum frequency of the first-order symmetric Lamb mode, where the group velocity of the Lamb wave goes to zero while the phase velocity remains finite. Experimental results with the laser source and receiver on epicenter demonstrate that the zero group velocity resonance generated with a low power modulated excitation source can be detected using an optical probe such as a Michelson interferometer coupled to a lock-in amplifier. This resonance peak is sensitive to the thickness and mechanical properties of plates and may be suitable, for example, for the measurement and mapping of nanoscale thickness variations.

Abstract: The invention relates to an ultrasonic medical imaging apparatus intended for analyzing an organic medium potentially including defects within a noisy structure. Ultrasound signals focused at a given depth according to M distinct successive excitations arc emitted and an image formation module makes it possible to obtain an image of said depth after reception of responses from the medium. The invention is such that the apparatus includes a module for using said responses for constructing a rectangular response matrix of dimension N*M, a coefficient Knm of which represents the response from the medium received by the transducer n following an excitation m, decomposing said response matrix into singular values, using the singular vectors corresponding to said singular values for locating singular zones corresponding to defects in the medium. Application: Ultrasonic apparatus particularly in the medical field.