Stipends of the Acoustical Society of America and the International Institute of Acoustics and Vibration for Russian students-acousticians

East European Acoustical Association:
ASA and IIAV scholars 2001

ASA scholars 2001

Name: Stanislav Yavorsky
Place of Work: Dep. of Ship and Industrial Acoustics, Krylov Shipbuilding Research Institute, Moskovskoe shosse, 44, Saint-Petersburg.
E-mail: syavorsky@mail.ru
Date of birth: 28.08.72
Education: post graduate student
Research title: Development of a method of estimation of low-frequency hydroacoustic fields, scattering from elastic thin-walled shells having internal saturation.
Main results:
It is known, that increase of amplitude of scattering can arise with scattering of low-frequency acoustic waves on elastic shells in liquid. Limited axis-symmetric thin-walled shells which have variable cross section are studied. Software for estimation of amplitude of scattering waves from such shells formed on the basis of a method of merging asymptotic decomposition developed by M.V.Fedoryuk, A.I.Boiko, and V.N.Valueva from N.N.Andreyev Acoustics Institute (Moscow) is created and tested. Experimental check on models of shells in hydroacoustical tank, and also comparison with results received by the help of the method of finite elements are made. Other acoustical studies carried out in 2000-2001 were devoted to acoustic properties of escalators tunnels of St. Petersburg underground, acoustic properties of bells made of untraditional alloys, and some acoustical features of Smolny Cathedral in St. Petersburg.
Main references:
1. A. Pyshin, L. Solovejtchik, Yu. Tikhomirov, S. Yavorsky Acoustics of the Smolny Cathedral in St. Petersburg, Journal of Building Acoustics, v.8, N1, 2001.
2. A. Pyshin, Yu. Tikhomirov, S. Yavorsky "Investigation of air noise characteristics on moving stairways of St. Petersburg's Metro" Proc. of 6-th International Symposium TRANSPORT NOISE AND VIBRATION, Saint-Petersburg, 4-6 June 2002 (on CD-ROM).

IIAV scholars 2001

Name: Feodor F. Legusha
Place of Work: St.Petersburg State Marine Technical University, 198262, St.Petersburg, Leninsky pr., 101.
E-mail: legusha@smtu.ru
Date of birth: 22.08.79
Education: post graduate student
Research title: Ultrasound method of increasing of wood density and shaping of the wood items.
Main results:
It is known that use of ultrasound in different technological processes leads increase of their economic and technical efficiency. Besides it was found that physics-mechanical parameters of the off-the-shelf items prepared on the base of ultrasound technology exceed those obtained on the base of the ordinary technology of the density increasing. Influence of intensive ultrasound wave on wood is studied in detail. Newest ultrasound technology of increasing the density and shaping of wood items is currently being developed. Methods of calculation of three-dimensional acoustical field in the wood blanks are in progress. General aims of these investigations are selection of optimal parameters of the field and determination of main technical parameters of device appropriated for wood density increasing. Methods of exciting of three-dimensional acoustical field in wood, influence of ultrasound on the plasticity of wood material at the stage of its density increasing and stabilization of physics-mechanical parameters of the off-the-shelf items are elaborated. Experimental device based on results of carried out studies is designed and constructed.
Main references:
1. Legusha F. F., Isakov N. Ya., Vasiliev B. P. "Development of the acousticthermooptical method of study of the physics parameters of piezoceramic", Scientific Report of the State Marine Technical University N0295.00011453, (1996).
2. Legusha F. F., Bochagov A. V., Legusha F. F. snr., Charitonov D. O. "Theoretical and experimental study of the dissipation processes of the energy in piezoceramic solids" Scientific Report of the State Marine Technical University N0195.00011452, (1996).
3. Legusha F. F., Bazarov S. M., Gurianov A. V., Legusha F. F. snr., Pugachev S. I. "Development of the device appropriated for the effect on the wood" Scientific Report of the State Marine Technical University N0187.014513, (1997)
4. Legusha F. F , Krasavina M. A., Legusha F. F. snr , Pugachev S. I. "Novel ultrasound technology of the increasing of the density and shaping of the items fabricated from the invaluable wood" Proceedings of the 3rd Russian Scientific Practical Conference "News in the ecology and security of life" 2, 102 (July 16-18, 1998, St. Peresburg, Russia)
5. Legusha F. F Legusha F. F. snr , Pugachev S. I. "Acousticthermooptical method of the measurement of the electro-physical parameters of piezoceramic". Proceedings of the 4th International Conference "Modern problems of the electronic equipment" 10, 77 (September 23-26,1998, Novosibirsk, Russia).
6. Legusha F. F., Legusha F. F. snr , Pugachev S. I "Measurement of the electrophysical parameters of piezoceramic by the acousticthermooptical method" Proceedings of the 4th International Conference "Modern problems of the electronic equipment" 1, 276 (September 23-26,1998, Novosibirsk).
7. Legusha F. F, Gerasimov N. P. Legusha F. F. snr , Moiseev N. N., Pugachev S. I "Absorption of the neutrons in the high density wood" Proceedings of the Scientific Technical Conference "100 years anniversary of the State Marine Technical University" Part 1, 60 (May, 1999, St. Petersburg, Russia).
8. Legusha F. F., Legusha F. F. snr , Pugachev S. I. "Ultrasound increasing of the density and shaping of the wood items" Proceedings of the Scientific Technical Conference "100 years anniversary of the State Marine Technical University" Part 1, 74 (May, 1999, St. Petersburg, Russia).
9. Legusha F. F., Scripetz S. V. "Measurement of the speed of sound in wood" Proceedings of the 7th Russian Scientific Conference of the graduate physicists and young scientists. p. 562 (2001, Ekatirenburg- St.Petersburg, Russia).
10. Legusha F. F., Scripetz S. V."Ultrasound method of the increasing density of wood" Proceedings of the 7th Russian Scientific Conference of the graduate physicists and young scientists. p. 563 (2001, Ekatirenburg- St.Petersburg, Russia).
11. Legusha F. F., Scripetz S. V., Charitonov D. O."Development of the physics-chemical method of joining unlike materials under the condition of the metalisation of piezoceramic in the presence of high frequency electric field" Scientific Report of the State Marine Technical University N01.20004901 (2000).
Name: Nikita Dementyev
Place of Work: Dep. of Hydrophysics, St.-Petersburg State Marine Technical University.
E-mail: nickdem@mail.ru
Date of birth: 18.11.74
Education: post graduate student
Research title: Influence of interception rib-stiffening on vibration of plate.
Main results:
Analytical investigations of features of interaction of elastic waves with a cross set of stiffeners were made. The research is based on a nontraditional method (method of summing of reflections). The essence of a method is based on adding of reflected from the ribs waves. The results of this work are the following. Equations for amplitude ratios on single obstacle, which describe wave transmission and reflection are elaborated. The ratios depend on frequency and angle of incident wave. Technique of calculation of flexural vibration of a plate with boundaries, partially reflecting waves is developed. The given technique allows to determine natural frequencies, modal angles, and modes and amplitude of vibration. A candidate of science dissertation entitled Research of the Vibrational Characteristics and Sound Radiation of Two-Hull Structures is derived. Following research has been done in the frame of the thesis. Analytical investigations of vibration of two-hull designs are conducted. A number of experiments on a test model of design in water and in air are carried out. Guidelines on designing of two-hull constructions are elaborated with the purpose of a decrease of levels of vibration on its elements. Analysis of sound radiation of similar designs in water and in air is planned to be done next years.
Main references:
1. A. V. Avrinski, N. Dementiev, V. F. Zhuravlev Ways of improvement of ship frames acoustical characteristics, Third international conference on shipbuilding, 2000.
2. A. V. Avrinski, N. Dementiev , Study of influence of rigidity edges cross-sections on plate vibration, Report St. Petersburg State Marine Technical University, #01.200.004899, 2000.