Dynamic analysis of prestressed laminated stepped spherical-cylindrical shells

A dynamic analysis model for the laminated spherical-cylindrical shell structures under prestress is established to investigate its vibration characteristics. Based on the first-order shear deformation theory, the constitutive equations of the structural system are derived. The displacement and rotational components of the shell segments are expanded using a combination of Jacobi polynomials and Fourier series. To handle the complexities of boundary conditions and interfacial continuity between substructures, virtual spring stiffness, treated as penalty parameters, is introduced, and the dynamic characteristics of the structure are solved using the Ritz method. The reliability and accuracy of the proposed method are verified through comparisons with results from existing literature and simulations data of finite element method (FEM). Additionally, prestress is applied through continuously distributed surface loads. The study focused on examining the effects of key factors, including prestress magnitude, structural dimensions, and boundary conditions, on the free and forced vibration characteristics of the stepped shell system. This investigation aimed to elucidate the intrinsic relationship between parameter variations and dynamic responses. The computational results can provide safety guidance for the preliminary design of composite shells under prestressed conditions in engineering applications.