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Information × Registration Number 0223U002078, 0120U105681 , R & D reports Title Analysis of the stress-strain state, vibrations and stability of compound shells of rotation, noncircular cylindrical shells with different cross sections and polygonal plates based on numerical and experimental approaches. popup.stage_title Head Grigorenko Olexander Ya., Доктор фізико-математичних наукHryhorenko Yaroslav M., Доктор технічних наук Registration Date 08-02-2023 Organization S.P. Tymoshenka Institute of Mechanics of the National Academy of Sciences of Ukraine popup.description2 The method of determining the critical limit and bifurcation values of the static load on the envelopes of rotation of the sign-changing curvature is presented. The calculation method is based on a nonlinear formulation of the problem using a dynamic stability criterion and a numerical-analytical approach to solving the corresponding nonlinear boundary-value problems and eigenvalue problems. The peculiarity of the approach is the rational reduction of the initial problem to a sequence of one-dimensional problems and the practically exact numerical solution of the latter. This makes it possible to take into account the meridian variable geometric and stiffness characteristics of the shell in a continuous form, which is especially important for corrugated type shells. The methodology is described, which allows to determine the stress-strain state of conical shells with sections based on the equations of the refined theory of shells. Solving equations for the cone were obtained from the initial equations. Equations for shells with slices were obtained by means of coordinate transformation. The finite element method for determining the frequencies and forms of free oscillations of polygonal plates of constant and variable thickness with different boundary conditions, as well as cylindrical shells of different cross-sections with closed and open contours with different variants of boundary conditions, is extended. The Rayleigh-Ritz method was extended and the frequency coefficients for calculating the frequencies of free oscillations of polygonal plates were specified. An experimental set-up and a method of conducting classical and non-classical experiments of Khladna were developed  Product Description popup.authors Boreiko Nataliia Petrivna Borisenko Maxim Yuriyovych Dokuchaieva Olha Mykolaivna Yaremchenko Serhiy Mykolayovych popup.nrat_date 2023-02-08 Close