Nonlinear FE Analysis of Orthotropic Steel Plates under Uniform Loads

This paper examines the nonlinear dynamic response of a thin orthotropic steel plate stiffened by longitudinal and transverse T-section ribs and subjected to a uniformly distributed harmonic load. The stiffened plate, representative of typical steel bridge, is modeled as a square orthotropic plate with two longitudinal and two transverse stiffeners. A geometrically, and mathematically nonlinear finite element model is developed in ABAQUS using the Dynamic/Implicit procedure. Four boundary conditions are investigated: fully simply supported (SSSS), fully clamped (CCCC), and two mixed cases (SCCS and SCSC). The numerical model is validated against the authors' previous analytical-numerical solution for a stiffened orthotropic plate under SSSS conditions, and the comparison confirms the adequacy of the proposed approach. The primary response quantities studied are the vertical displacement at the plate center and the total internal strain energy. The results show that the SSSS boundary condition leads to the largest central displacement and the highest stored strain energy, due to the greater rotational freedom and lower effective bending stiffness. In contrast, the CCCC condition produces the smallest displacement and minimum strain energy, while the SCCS and SCSC configurations exhibit intermediate behavior. These findings demonstrate the significant influence of edge restraints on the nonlinear dynamic performance of stiffened orthotropic steel plates and provide useful guidance for their design under dynamic loading.

کلیدواژه ها:

Orthotropic stiffened steel plate ، Nonlinear dynamic response ، Harmonic loading ، Boundary conditions ، Finite element analysis