DESIGNING AND DETAILING OF BUILDING SYSTEMS. MECHANICS IN CIVIL ENGINEERING

Fluctuations of the membrane with piecewise smooth contour and mixed boundary conditions

Vestnik MGSU 11/2015
  • Algazin Sergey Dmitrievich - Ishlinsky Institute for Problems in Mechanics of the Russian Academy of Sciences (IPMekh RAN) leading research worker, chief research worker, Ishlinsky Institute for Problems in Mechanics of the Russian Academy of Sciences (IPMekh RAN), 101-1 Prospekt Vernadskogo str., Moscow, 119526, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 29-37

The eigenvalue problem for the two-dimensional operator Laplace is classical in mathematics and physics. However, computing methods for calculation of eigenvalues have still many problems, especially in applications to acoustic and electromagnetic wave guides. The investigated below two-dimensional spectral for the Laplace operator have been previously considered by the author only in smooth areas. The solutions of these tasks (eigen functions) are infinitely differentiated or. even analytical and therefore in order to create effective algorithms it is necessary to consider this enormous a priori information. Traditional methods of finite differences and finite elements almost do not practically use the information on smoothness of the decision, i.e. these are methods with saturation. The term “saturation” was entered by K.I. Babenko. Using the method of computing experiment the author investigates the task about fluctuations of the membrane with the piecewise smooth contour for two-dimensional area, obtained by conformal representation of the square. It is shown that eigen functions are infinitely differentiated. Therefore, numerical algorithms without saturation are applicable. In article the calculation algorithm of eigenvalues in this two-dimensional area is developed, which allows determining up to 10 natural frequencies with the accuracy acceptable for practice on the grid 10×10.

DOI: 10.22227/1997-0935.2015.11.29-37

References
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