Abstract
A modification of the combined SAFT (C-SAFT) method for reconstructing reflector images in a test object, which consists of several regions with different acoustic properties, in particular, anisotropy properties, is proposed. A method for the direct construction of a family of rays, which exit from the point where a transmitter is positioned, is used to calculate the ray trajectories with consideration for the anisotropy. After the family of rays is constructed, it is possible to analyze their attribution to a certain acoustic scheme and to approximate the calculated delays on the spatial grid of the region of iterest (ROI). This will allow one to calculate the pulse travel time from a transmitter to any point of the ROI and back to the receiver and to use the C-SAFT method for reconstructing reflector images. During processing of echo signals that were calculated in the CIVA program, the efficiency of the proposed method was demonstrated. Accounting for the anisotropy in a model experiment increased the focusing quality when reconstructing images of side-drilled holes in a specimen with a repair weld.
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Bazulin, E.G., Comparison of systems for ultrasonic nondestructive testing using antenna arrays or phased antenna arrays, Russ. J. Nondestr. Test., 2013, no. 7, pp. 404–423.
Kovalev, A.V., Kozlov, V.N., Samokrutov, A.A., Shevaldykin, V.G., and Yakovlev, N.N., Pulsed echo method in concrete testing. Noise and spatial selection, Defektoskopiya, 1990, no. 2, pp. 29–41.
Bazulin, E.G., On the possibility of using the maximum entropy method in ultrasonic nondestructive testing for scatterer visualization from a set of echo signals, Acoust. Phys., 2013, vol. 59, no. 2, pp. 210–227.
Samokrutov, A.A. and Shevaldykin, V.G., On the possibility of evaluating the character of a metal discontinuity flaw using an ultrasonic tomograph with digital focusing of the antenna array, Kontr. Diagnost., 2011, no. 10, pp. 63–70.
Chatillon, S., Fidahoussen, A., Iakovleva, E., and Calmon, P., Time of flight inverse matching reconstruction of ultrasonic array data exploiting forwards models, NDT in Canada, 2009, National Conf., 2009.
Fedorov, F.I., Teoriya uprugikh voln v kristallakh (Theory of Elastic Waves in Crystals), Moscow: Nauka, 1965.
Petrashen’, G.I., Rasprostranenie voln v anizotropnykh uprugikh sredakh (Propagation of Waves in Anisotropic Elastic Media), Leningrad: Nauka, 1980.
Connolly, G.D., Modelling of the propagation of ultrasound through austenitic steel welds, UK Research Centre in NDE (RCNDE), Department of Mechanical Engineering Imperial College, London: SW7 2AZ, 2009.
Landau, L.D. and Livshits, E.M., Teoreticheskaya fizika. V 10-i tomakh. T. VII. Teoriya uprugosti: Uch. posobie. 4-oe izd., ispr. i dop (Theoretical Physics, in 10 vols. Theory of Elasticity: Manual), 4th Ed., Moscow: Nauka, 1987.
Rinkevich, A.B., Smorodinskii, Ya.G., Volkova, N.N., and Zagrebin, V.N., Group velocity of ultrasound in transversally isotropic medium, Defektoskopiya, 1994, no. 1, pp. 58–63.
Barkhatov, V.A., Modeling of ultrasonic waves by the finite-difference method in the time domain: a two-dimensional problem: optimal algorithms, analysis of errors, and absorbing ranges near the grid boundaries, Russ. J. Nondestr. Test., 2009, no. 6, pp. 410–424.
Ernst, H., Dressler, K., Trautmann, H., and Wüstenberg, H., Visualization of ultrasonic fields in anisotropic stainless steel castings, 7th Intern. Conf. on NDE in Relation to Structural Integrity for Nuclear and Pressurizedf Components, Yokohama, Japan, 2009. http://www.ndt.net/article/jrc-nde2009/papers/41.pdf
Bazulin, E.G., Reconstruction of images of reflectors using the correlation method at an arbitrary number of reflections of an ultrasonic pulse from the boundary of a test object that consists of regions with different acoustic properties, Russ. J. Nondestr. Test., 2014, no. 9, pp. 515–530.
Moysan, J., Gueudre, C., Ploix, M.-A., Corneloup, G., Guy, P., and Chassignole, B., Advances in ultrasonic testing of austenitic stainless steel welds. Towards a 3d description of the material including attenuation and optimization by inversion, Ultrasonic Wave Propagation in Nonhomogeneous Media. Series: Springer Proc. in Physics, 2009, vol. 128, pp. 15–24. DOI 10.1007/978-3-540-89105-5.
Connolly, G., Lowe, M., Roklin, S., and Temple, A., Imaging of defects in austenitic steel welds using an ultrasonic array, Ultrasonic Wave Propagation in Nonhomogeneous Media. Series: Springer Proc. in Physics, 2009, vol. 128, pp. 25–38. DOI 10.1007/978-3-540-89105-5.
Bazulin, E.G. and Ismailov, G.M., Simultaneous measurement of the velocity of an ultrasonic shear wave and the thickness of a test object with plane-parallel boundaries using two antenna arrays, Russ. J. Nondestr. Test., 2013, no. 8, pp. 446–457.
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Original Russian Text © E.G. Bazulin, 2015, published in Defektoskopiya, 2015, Vol. 51, No. 4, pp. 42–52.
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Bazulin, E.G. Reconstruction of reflector images using the C-SAFT method with account for the anisotropy of the material of the test object. Russ J Nondestruct Test 51, 217–226 (2015). https://doi.org/10.1134/S1061830915040026
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DOI: https://doi.org/10.1134/S1061830915040026