Journal of Dynamics and VibroacousticsJournal of Dynamics and Vibroacoustics2409-4579Samara National Research University280610.18287/2409-4579-2016-3-1-47-54UnknownVIBROACOUSTIC DIAGNOSTICS OF OPEN-TYPE (UN-PRESSURIZED) SPACECRAFTSLysenkoE. A.mla340@iss-reshetnev.ruBernsV. A.v.berns@yandex.ruAcademician M.F. Reshetnev Information Satellite Systems 52, Lenin st., Zheleznogorsk,
Krasnoyarsk region, 662972, Russian FederationSiberian Aeronautical Research Institute named after S.A. Chaplygin 21/1, Polzunov st., Novosibirsk, 630051, Russian Federation160320163147540812201518012016Copyright © 2017, Journal of Dynamics and Vibroacoustics2017<p><em>A special feature of the open design spacecraft is the presence of a CFRP (carbon-fiber reinforced plastic) cylinder around which three-layered honeycomb panels are fixed by means of pylons. The electronic equipment, antenna and feeder relay systems, units and instruments of the satellite control system are installed on these panels. Vibration loading of such structures is proposed to carry out both with the help of an electrodynamic shaker (up to 100 Hz) and a diffuse sound field in the reverberation chamber. The structure response to acoustic and vibration loading is fixed by accelerometers and presented in the form of amplitude-frequency characteristics and the power spectral density function of the random signal from the vibration frequency. The spacecraft defects are determined by parametric variations of its vibration response. To do this, vibration and acoustic tests are carried out in three stages. At the first stage the probing vibration loading the structure with low intensity is performed. Test results - resonant frequencies and vibration amplitudes are compared with the design values or the values defined at the ground experimental development of the spacecraft. At the second stage the tests are performed at high loads, but in safe modes, calculated by a special technique. The third stage is a repetition of the first one. As a result, the defect location and nature are determined by the vibration parameters deviations. The article presents the methodology main statements and the spacecrafts vibroacoustic diagnostics results. It is concluded that the use of such diagnostics in the final stages of products manufacturing is reasonable.</em></p>Open-type spacecraft, acoustic test, reverberation chamber, vibration test, electrodynamic shaker, structural defects, diagnostics by vibration parameters.Космический аппарат открытого исполненияакустические испытанияреверберационная камеравибрационные испытанияэлектродинамический вибростенддефекты конструкциидиагностика по параметрам вибраций.[[1] Inventor's Certificate. 1111046 USSR, MKI G 01 M 7/00. Control method of the frequency test mode / V.K. Merkulov, S.A. Lozhnikov, E.A. Lysenko (USSR). no. 3600006 / 25-28; appl. 28/02/83; publ. 30/08/84, Bul. no. 32.][[2] Berns, V.A. (2012), Diagnostika i kontrol' tekhnicheskogo sostoyaniya samoletov po rezul'tatam rezonansnykh ispytanii: monografiya [Diagnostics and monitoring of the aircraft technical condition by the result of resonance tests: monography], Publishing House of the NSTU, Novosibirsk, 272 p. (in Russian).][[3] Lysenko, E.A., Evtifiev, M.D., Halimanovich, V.I. and Shatrov, A.K. (2005), Vyiavlenie defektov kosmicheskikh apparatov v protsessakh ispytanii na vibratsionnye i akusticheskie vozdeistviia v ispytatel'noi laboratorii [Detection of spacecraft defects in vibration and acoustical testing in the test laboratory], Vestnik SibGAU [SibSAU Bulletin], no. 6, pp. 174-178. (in Russian).][[4] Lysenko, E.A., Evtifiev, M.D., Halimanovich, V.I. and Akimov, A.N. (2006), Algoritm analiza eksperimental'nykh dannykh i rascheta rezhima nagruzheniia pri vibratsionnykh ispytaniiakh kosmicheskogo apparata [Algorithm of experimental data analysis and loading mode calculation during a vibration test of spacecraft], Vestnik SibGAU [SibSAU Bulletin], no. 1 (8), pp. 73-75. (in Russian).][[5] Motylev, N.I. (2004), Vyiavlenie mekhanicheskikh defektov v elementakh reaktorov i konstruktsii AES pri testovykh vibroudarnykh vozdeistviiakh [Detection of mechanical defects in the elements of NPP reactors and structures under test vibroimpact], Tekhnologii i sistemy obespecheniia zhiznennogo tsikla iadernykh energeticheskikh ustanovok [Technology and systems of nuclear power plants life cycle support], Mendeleev, St. Petersburg, Issue 2, pp. 126-131. (in Russian).][[6] Postnov, V.A. (2000), Opredelenie povrezhdenii uprugikh sistem putem matematicheskoi obrabotki chastotnykh spektrov, poluchennykh iz eksperimenta [Determination of elastic systems damages by mathematical treatment of frequency spectra obtained from the experiment], Mekh. tverd. tela, izv. RAN [Mechanics of Solids, proc. of the Russian Academy of Sciences], no. 6, pp. 155-160. (in Russian).][[7] Postnov, V.A. and Shlottmann, G. (2004), Opredelenie povrezhdenii uprugikh sistem putem matematicheskoi obrabotki chastotnykh spektrov, poluchennykh iz eksperimenta [Application of experimental data on the elastic systems dynamic properties changing in problems of structural damages assessment], Vestnik NNGU, Seriia Mekhanika [NNSU Bulletin, Mechanics], no. 1, pp. 32-42. (in Russian).][[8] Shevelev, N.A. and Dombrowskii, I.V. (2009), Chislennoe issledovanie dinamicheskikh kharakteristik elementov konstruktsii s defektami formy [Numerical study of dynamic characteristics of structural elements with shape defects] Vestnik PGTU, Mekhanika [PSTU Bulletin, Mechanics], no. 1, pp. 160-163. (in Russian).][[9] Perera, R. Fang, S. E. and Huerta, C. (2009), Structural crack detection without updated baseline model by single and multiobjective optimization, Mechanical Systems and Signal Processing, Vol. 23, no. 3, pp. 752–768.]