Análise de estabilidade de risers rígidos pelo método dos elementos finitos

Abstract

The analysis of the critical load is essential in the process design of laminated tubes subject to external pressure. These tubes may suffer local buckling of the tube wall, such as shell buckling. Moreover, it is important to consider the initial geometrical imperfections caused by the manufacturing process since cylindrical shells are very sensitive to load and geometric imperfections. Closed form expression and knock-down factor for orthotropic cylindrical shells are also found in the literature. These expressions have also been used for composite shells, but their applicability needs to be investigated since the buckling load of laminated composite shells depend not only on the geometry, boundary conditions and material properties, but also on the thickness, orientation and sequence of the laminas. The present paper determine the buckling load of laminated tubes subjected to external pressure through the Finite Element Method (FEM). Perfects tubes with different lamination schemes will be considered. The FE numerical results will be compared with experimental results found in the literature and used to assess the validity of the approximated closed-form expressions used for design purposes.