Effect of Multiple Annular Plates on Vibration Characteristics of Laminated Submarine-like Structures

Materials (Basel). 2022 Sep 13;15(18):6357. doi: 10.3390/ma15186357.

Abstract

A numerical model for the prediction of vibration behaviors of a laminated submarine structure consisting of spherical, cylindrical, and cone shells with multiple built-in annular plates is reported in this article. With the aid of the first-order shear deformation theory (FSDT) concerning plates and shells, the energy expressions of each substructure are derived. The displacement functions in the energy functionals are expanded by the employment of Legendre orthogonal polynomials and circumferential Fourier series. Then, the Rayleigh-Ritz procedure is performed to obtain the eigenfrequency and the corresponding eigenmode of the submarine model. The correctness of the structural model is examined by comparing the results with existing papers and the finite element method, and the maximum deviation is not more than 2.07%. Additionally, the influence of the plate's thickness, position, inner diameter, as well as the laying angle on the intrinsic vibration characteristics of laminated submarine-like structure is determined. The results reveal that rational geometry design and assemblage benefit the vibration performance of the combination. Increasing the thickness of all the annular plates, decreasing the inner radius, and regulating the laminated scheme, make remarkable influence on structural free vibration, with the maximum relative changing rate of frequency exceeding 97%, 16%, and 23%, respectively.

Keywords: Rayleigh–Ritz technology; annular plate; laminated submarine-like model; vibration analysis.

Grants and funding

This research was funded by the National Natural Science Foundation of China (Grant No. 51705537). The authors gratefully acknowledge the financial support from the Postgraduate Scientific Research Innovation Project of Hunan Province. This research is also supported by the Fundamental Research Funds for the Central Universities of Central South University (Grant No. 2022ZZTS0174).