Application of 6-DOFs meshfree modeling to linear buckling analysis of stiffened plates with curvilinear surfaces

A buckling analysis of stiffened plates including curvilinear surfaces is carried out by an effective meshfree model. The buckling loads and modes computed by the present method are analyzed. Six degrees of freedom (6-DOFs) curved shell meshfree formulation in a convected coordinate system including a drilling rotation component is employed, which enables the assembly of curved shells for the modeling of more complex structures. By this formulation, the assembly of any arbitrary shape of geometry can be modeled in convected coordinates, while the 5-DOFs shell formulation suffers from the modeling of shell assemblies. Particularly, curved shells with straight stiffeners and plates with curvilinear stiffeners are considered. Furthermore, a twisted T-shaped structure where both web and flange have curvilinear geometry is analyzed. A meshfree discretization is employed, with which the reproducing kernel particle method is used as the meshfree interpolant. A boundary singular kernel method is adopted to precisely impose an essential boundary condition and to model folded shell geometries. The accuracy and effectiveness of the proposed method are demonstrated by several shell buckling problems for stiffened plate structures with curvilinear surfaces. The obtained meshfree results are compared with the linear and quadratic shell element results of finite element method ANSYS and discussed.