Nonlinear Finite Element Analysis of Pressurized Spherical Shell for Deep Water Structure

One of the main problems in developing the deep water structure is the stability of the pressurized spherical shell. If the pressurized spherical shell belongs to moderate thick shell, the transverse shear deformation must be taken into account. Based on the nonlinear finite element method, the stability of the pressurized spherical shell under deep water was studied in this paper. The influence of out of roundness due to the machining, the interaction between material nonlinear and geometry nonlinear were considered. They are caused by material yield, strain intensifying and big plastic deformation of the whole shell structure buckling. Results from calculation showed that the critical buckling pressure decreases with the increasing of the radius under the same thickness but increases with the thickness under the same radius. The relationship charts of the critical buckling pressure, the thickness, the radius of the pressurized spherical shell were derived. The reasonable geometric parameters were then selected.