Free vibration analysis of perforated composite cylindrical shell and panel using multi-domain generalized differential quadrature (GDQ) method

Abstract

Free vibration behavior of a composite shell/panel with and without a central square cutout has been studied using Multi-domain Generalized Differential Quadrature (GDQ) method. A physical domain is decomposed into several elements in such a way that all the elements have uniform thickness and material properties, as well as continuous loading and boundary conditions at their edges. The governing equations are derived based on the first-order shear deformation theory. They are formulated in a general form and can be converted to Donnell’s, Love’s, and Sanders’ theories. In addition, compatibility conditions are considered at the interface boundaries of adjacent elements as well as proper boundary conditions on other elements edges. The GDQ method is employed to discretize these equations in both longitudinal and circumferential directions. By assembling these discretized relations, a system of algebraic equations will be generated. These equations can be solved throughan eigenvalue solution to compute the natural frequencies of the whole shell/panel. Numerical results obtained by the presented method are compared with ABAQUS results and those available in the literature. After verifying the accuracy and precision of the proposed method, it is employed to study the effect of an opening on the vibrational behavior of composite shells and panels through a parametric study. The influence of the presence of a cutout and its size is investigated on shells/panels with various material properties, layup orientations, thicknesses, dimensions, and boundary conditions. The obtained results can be used as a benchmark for further researches.