Free vibration analysis of inversely coupled composite laminated shell structures with general boundary condition

In this paper, the free vibration characteristics of various coupled composite laminated doubly curved revolution shells are investigated under generalized boundary conditions (BCs). The joint shell structure consists a shell–cylindrical shell–doubly structure, and here, unlike previous structures, inversely joined together. such as elliptical, paraboloidal, spherical considered. first order shear deformation theory multi-segment partitioning technique adopted to establish theoretical model structures. Regardless individual structures BCs, displacement functions each segment expanded using ultraspherical polynomials in meridional direction standard Fourier series circumferential direction. generalize BCs at both ends connecting interface, virtual spring is employed. Then, natural frequencies mode shapes obtained by Ritz method. reliability accuracy proposed method verified convergence study numerical comparison with results finite element addition, some also reported for classical elastic which can provide reference data future studies.