Static analysis of thick laminated shells with different boundary conditions using GDQ

Equilibrium equations and the associated boundary conditions for doubly curved, relatively deep and thick composite shells are shown. Two First Order Shear Deformation theories (FSDTs) are used. The first one uses plate stiffness parameters for thick shells and the other includes the effect of curvature in the calculation of stiffness parameters. Equilibrium equations are put together with the equations of stress resultants to arrive at a system of seventeen first order differential equations. These equations are solved numerically with the aid of General Differential Quadrature (GDQ) method for isotropic, cross-ply, angle-ply and general lay-up cylindrical shells with six types of different boundary conditions using above mentioned theories. Results obtained using both theories are compared with the available results in literature and those obtained using a three-dimensional (3D) analysis to test the accuracy of the shell theories presented here.