Characterisation of ultrasonic structural noise in multiple scattering media using phased arrays

11th Anglo-French Physical Acoustics Conference

Bedetti, T.^1 ; Dorval, V.^1 ; Jenson, F.^1 ; Derode, A.^2

CEA, LIST, F-91191 Gif-sur-Yvette cedex, France^1

Institut Langevin, Université Paris Diderot-Paris 7, CNRS UMR 7587, 10 rue Vauquelin, 75005 Paris, France^2

关键词: Backscattered intensity;    Coherent backscattering;    Linear phased arrays;    Multiple scattering process;    Multiple-scattering media;    Post-processing techniques;    Stainless steel plate;    Ultrasonic inspections;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/457/1/012003/pdf
DOI  :  10.1088/1742-6596/457/1/012003

来源: IOP

【 摘 要 】

The ultrasonic inspection of multiple scattering media gives rise to structural noise which makes it difficult to detect potential damage or crack inside the component. In order to predict the performances of ultrasonic inspection over such complex media, scattering models can be used. Such models rely on specific key parameters describing the multiple scattering process, which can be determined by specific measurements and post-processing techniques. Such experiments were carried out on stainless steel plates using linear phased-arrays. They consist in recording the response matrix constituted by impulse responses between all the elements of the array. By conducting post-processing on this matrix, we measure the elastic mean free path le and the correlation distance dc of the recorded noise. Additionally, the dynamic behaviour of the coherent backscattering effect was studied in order to measure the diffusion constant D. Plane-wave beamforming has been applied to the response matrix to improve the angular resolution and the signal-to-noise ratio of the backscattered intensity. Details of postprocessing techniques will be shown.