10.14489/td.2016.01.pp.046-050

2016, 01 January

DOI: 10.14489/td.2016.01.pp.046-050

Nesmashny E.V., Kazakov N.A.

TO A QUESTION OF EXCITATION OF LAMB WAVES BY AE-SOURCES IN THICK-PLATE CONSTRUCTIONS
(pp. 46-50)

Abstract. It is discussed the conflict of Rayleigh and Lamb decisions to extend short pulses on the free surface of thickwalled sheet constructions. It is provided the proofs of existence of lost on known curves of dispersion of the longitudinal and cross modes of the waves of Lamb important for specification of the theory of frequency and geometrical dispersion of phase speed and amplitudes of signals of AE which are completely not dispersing on speed. It is briefly proved the basic for AE question of impossibility of an internal source of excitation of Rayleigh wave in the sheet and the main mode a0 , and also mode s0 in Rayleigh area of its existence. It indicates the possibility of excitation of the main longitudinal and transverse modes of Lamb waves, which is non dispersant for the speed of distribution, at influence of an internal source of volume sv-waves in a sheet at their reception through a contact layer, respectively, solid-state and liquid type.

Keywords: acoustic emission, wave mode, phase speed, dispersion, thick-plate, wave thickness, excitation of mode, matching, AE source.

+ - About the Authors Click to collapse

E. V. Nesmashny, N. A. Kazakov
Krylov State Research Centre, St. Petersburg, Russia. E-mail: Данный адрес e-mail защищен от спам-ботов, Вам необходимо включить Javascript для его просмотра.

+ - References Click to collapse

1. Nesmashnyi E. V., Kazakov N. A. (2012). Analysis of the frequency-velocity dispersion and geometrical amplitudes of lamb waves in relation to the problems of acousticemission diagnostics sheet structures. Kontrol'. Diagnostika, (8), pp. 5-11.
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