On the circumferential wave responses of connected elliptical-cylindrical shell-like submerged structures strengthened by nano-reinforcer

This paper is devoted to estimate the dynamic performance related to Connected Elliptical-Cylindrical Shells (CECSs), which can be applicable in submerged structures. Conducive to progress the vibrational behavior associated with the homogenous CECS, nanocomposite materials including Graphene Nano Platelets (GNP) nano reinforcer are used. It is obvious that the corresponding mechanical criteria of nanocomposite counting polymer and GNP nano-reinforcer are required for obtaining the governing formulation. Halpin-Tsai and the rule of mixture schemes are utilized for predicting the equivalent density, Poisson's ratio, and Young's modulus. Furthermore, various patterns are registered for the distribution of GNP nano-reinforcer along with the thickness of the CECSs. According to the obtained equivalent mechanical characteristics, by means of Hamilton's concept, the governing motion equations of CECSs are achieved as well. Moreover, the effect of shear deformation is considered subject to the First Order Shear Deformation Hypothesis (FOSDH). Afterward, a professional semi analytical approach, licensed the Generalized Differential Quadrature (GDQ) scheme, is employed for discretizing the differential equations at different separator points throughout the longitudinal (for the cylindrical part) and meridional (for the elliptical section) direction of the structure. By solving an eigenvalue problem, the natural frequencies of CECSs having different types of Boundary Conditions (BCs) can be evaluated numerically. First, a validation study is performed to prove the correctness and accuracy of the proposed formulation. Then, several novel and complex problems are analyzed numerically and the effects of different parameters including boundary conditions, geometric properties, and material characteristics on the frequency parameter of CECSs are also investigated.

Automated summary

This paper investigates the dynamic performance of Connected Elliptical-Cylindrical Shells (CECSs) using nanocomposite materials. The equivalent mechanical characteristics of the CECSs are obtained, and the natural frequencies of CECSs with different boundary conditions are numerically evaluated. The effects of various parameters on the frequency parameter of CECSs are also studied.