Vibrational characteristic simulations regarding connecting two different semi-spheroidal shells and a full-spheroidal shell with a conical shell categorized in underwater structures

Abstract

Recently, the related structures of marine, underwater, and ocean structures, covering, ice-breaking devices, riser pipes, ballast water gears, gliders, and underwear noise migrations, can be counted by Connected Shells (CSs). Accordingly, for the first time, the investigation related to vibration outputs associated with connecting two different semi-spheroidal shells and a full-spheroidal shell with a conical shell, namely Connected Spheroidal-Conical Shell Assembly (CSCSA) organized in three assembly groups is examined here. In detail, General Shell Hypothesis (GSH) and the First Shear Deformation Theory (FSDT) are connected to find the main formulations of the CSCSAs' shell elements. Addedly, the Motion Governing Differential Equations (MGDEs) associated with each shell element related to the CSCSAs are identified as implementing Hamilton's principle. Addedly, the MGDEs associated with the CSCSA components are discretized, realizing the Generalized Differential Quadrature Method (GDQM). Thereafter, the Natural Frequency Factors (NFFs) of the CSCSAs are determined by implementing the eigenvalue determination. Also, the NFFs measured by the suggested context are linked to the NFFs determined using classical FEM-constructed commercial software to validate the provided approach since previous research has not been conducted on these structures in the literature (except one type related to the CSCSAs). More importantly, the largest observed inaccuracy is less than 1%. Consistent with this, the responses of this investigation may be operated as the benchmark. Finally, the impacts of the geometrical parameters connected to the CSCSAs on the NFFs of the structure are identified via the design and solution of original cases.