Summary
An approximate method is presented for determining the probabilistic response of rectangular orthotropic plates clamped all round. For solving the stochastic boundary value problem, the probabilistically given and sought functions are expressed in terms of series of approximate modes of vibration, which satisfy the boundary conditions but not the field equation. Galerkin's procedure then yields a set of linear equations for the cross-spectral densities of the displacements. The cross-spectral density of the external pressure is taken to be a product of longitudinal and transverse correlation coefficients which depend on frequency and separation distance.
When the approximate method presented here is applied to cases capable of closed solutions (i.e. plates having a pair of opposite edges simply supported), the result coincides with that obtained by the classical normal-mode approach.
Zusammenfassung
Eine Näherungsmethode zur Berechnung der stochastischen Antwort von rechteckigen, orthotropen Platten mit allseitig eingespannten Rändern wird angegeben. Zur Lösung des stochastischen Randwertproblems werden die gegebenen und gesuchten Funktionen durch angenäherte Eigenfunktionen dargestellt, die die Randbedingungen, aber nicht die Bewegungsgleichungen erfüllen. Das Galerkin-Verfahren liefert dann einen Satz von linearen Gleichungen für die Kreuzspektraldichten der Verschiebungen. Die Kreuzspektraldichte der äußeren Belastung wird als Produkt der Korrelationskoeffizienten in Längs- und Querrichtung der Platte angenommen.
Wendet man das hier angegebene Näherungsverfahren auf Fälle an, die Lösungen in geschlossener Form erlauben, so stimmen die Ergebnisse mit denen überein, die man nach der klassischen Modalverschiebungsmethode erhält.
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References
Crandall, S. H., Mark, W. D.: Random Vibration in Mechanical Systems. New York: Academic Press. 1963.
Lin, Y. K.: Probabilistic Theory of Structural Dynamics. New York: McGraw-Hill. 1967.
Bolotin, V. V.: Statistical Methods in Structural Mechanics (translated by S. Aroni). San Francisco: Holden Day Inc. 1969.
Parkus, H.: Random Processes in Mechanical Sciences. Udine: International Center for Mechanical Sciences. 1969.
Powell, A.: On the approximation to the “infinite” solution by the method of normal modes for random vibrations. Journal of the Aeronautical Society of America30, 1136–1139 (1958).
Bolotin, V. V.: On elastic vibrations excited by broadband random forces. Izvestiya Vyschykh Uchebnych Zavedenii, No. 3 (1963).
Pal'mov, V. A.: Thin shells acted on by broadband random loads. Journal of Applied Mathematics and Mechanics29, 905–913 (1965).
Ribner, H. S.: Response of flexible panel to turbulent flow: running wave versus modal density analysis. Journal of the Acoustical Society of America40, 721–726 (1966).
Strawderman, W. A.: Turbulent-induced plate vibrations: an evaluation of finite—and infinite-plate models. Journal of the Acoustical Society of America46, 1294–1307 (1969).
Elishakoff, I., Efimtsoff, B.: On the vibrations of unbounded plates and the field of random forces. Soviet Applied Mechanics8, 903–906 (1972).
Elishakoff, I.: Distribution of natural frequencies in certain structural elements. Journal of the Acoustical Society of America57, 361–369 (1975).
Dowell, E. H.: Comments on “Turbulent-induced plate vibrations: an evaluation of finite- and infinite-plate models” Journal of the Acoustial Society of America49, 376 (1971).
Dyer, I.: Response of plates to a decaying and convecting random pressure field. Journal of the Acoustical Society of America31, 922–928 (1959).
Clarkson, B. L.: Stresses in skin panels subjected to random acoustic loading. The Aeronautical Journal of the Royal Aeronautical Society72, 1000–1010 (1968).
Crocker, M. J.: The response of a supersonic transport fuselage to boundary layer and to reverberant noise. Journal of Sound and Vibration9, 6–20 (1969).
Strawderman, W. A.: Turbulent-flow-excited vibration of a simply supported, rectangular flat plate. Journal of the Acoustical Society of America45, 177–192 (1969).
Wagner, H., Rama Bhat, B.: Linear response of an elastic plate to actual random load. Ingenieur Archiv30, 149–158 (1970).
Elishakoff, I.: Vibration analysis of clamped square orthotropic plates. American Institute of Aeronautics and Astronautics Journal12, 921–924 (1974).
Dimentberg, M. F.: Forced vibrations of panels under space-time random loading. Inzhenernyi Zhurnal1, No. 2, 97–105 (1961).
Bolotin, V. V.: An asymptotic method for the study of the problem of eigenvalues for rectangular regions, in: Problems in Continuum Mechanics (Volume dedicated to N. I. Muskhelishvili), pp. 56–68. Philadelphia, Pa.: Society of Industrial and Applied Mathematics. 1961.
Chyu, W. J., Au-Yang, M. K.: Random response rectangular panels to the pressure field beneath a turbulent boundary layer in subsonic flows. NASA TND-6970, 1972.
Warburton, C. B.: The Dynamical Behaviour of Structures. New York: Pergamon Press. 1964.
Huffington, J., jr., Hoppmann, N. H.: On the transverse vibrations of rectangular orthotropic plates. Journal of Applied Mechanics25, 389–395 (1959).
Powell, A.: An introduction to acoustic fatigue, in: Acoustic Fatigue in Aerospace Structures (Trapp, W. J., Forney, D. M., jr., eds.), pp. 1–15. 1965.
Elishakoff, I.: On the determination of spectral densities of external forces of plates and shells, in: Reliability Problems in Structural Mechanics (Bolotin, V. V., Čyras, A. A., eds.), pp. 36–44. Vil'nius. 1971.
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Elishakoff, I. Random vibrations of orthotropic plates clamped or simply supported all round. Acta Mechanica 28, 165–176 (1977). https://doi.org/10.1007/BF01208796
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DOI: https://doi.org/10.1007/BF01208796