A data-driven enhanced generalized differential quadrature algorithm in free vibration analysis of shells of revolution with free-form meridian and their combined structures

In this paper, a data-driven enhanced generalized differential quadrature (DE-GDQ) algorithm in free vibration analysis is proposed, which can be applied to shells of revolution with free-form meridian and their combined structures. According to first order shear deformation theory (FSDT) and Hamilton's principle, the governing equation for doubly-curved shells is obtained. The general boundary conditions are considered through artificial springs. Then the GDQ is introduced to solve the governing equations and the DE-GDQ is proposed on the basis of GDQ. After a detailed solution procedure of DE-GDQ is introduced and the convergence analysis is finished, multiple models and boundary conditions are validated including shells of revolution with conic section meridian, Haack series meridian, rational Bézier curve meridian. Isotropic materials and anisotropic materials including functionally graded (FG) materials are both verified. The free vibration analysis of combined structures is also finished and compared with finite element method (FEM). The comparison among DE-GDQ, GDQ and FEM shows that the DE-GDQ has greater advantages in terms of calculation efficiency, accuracy, and scope of application.