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Ultrasonic array imaging in unknown anisotropic nuclear steels from the nuclear field using optimization algorithms
Abstract : The ability of an adaptive ultrasonic imaging procedure to inspect
inside unknown anisotropic nuclear steels, such as V-shape welds or cladded components, is investigated herein. The
optimization scheme combines the Total Focusing Method (TFM) imaging algorithm with a customized
gradient ascent method in order to improve both the quality and reliability of ultrasound images.
A statistical analysis of its robustness is performed with simulated echoes and using a surrogate
model in order to speed up the computation times of TFM images. Then, the optimization procedure is
evaluated on several experimental cases and it provides highly enhanced images with a 5 MHz
array. The positioning of the artificial defects of 1.5 mm diameter is estimated with less than 1
mm error with respect to their actual positions, and the signal-to-noise ratio is increased by up to
10 dB. The elastic properties are also estimated with less than 10% error when compared to actual
material properties.
https://hal-centralesupelec.archives-ouvertes.fr/hal-02475497
Contributor : Dominique Lesselier <>
Submitted on : Wednesday, February 12, 2020 - 9:58:01 AM
Last modification on : Monday, February 17, 2020 - 10:22:02 AM
Contributor : Dominique Lesselier <>
Submitted on : Wednesday, February 12, 2020 - 9:58:01 AM
Last modification on : Monday, February 17, 2020 - 10:22:02 AM
