Nonlinear bending analysis of ring-stiffened functionally graded circular plates under mechanical and thermal loadings

• Large deflection of ring-stiffened FG circular plates is investigated, using DR method.
• Through increase of stiffener depth, the effect of temperature dependency is increased.
• The larger values of thermal gradient have the less effecton the results with simply support.

The large deflection behaviors of ring-stiffened shear deformable functionally graded (FG) circular plates under mechanical and thermal loadings are investigated. Material properties of the FG plate are assumed to be temperature dependent, and graded through the thickness according to the power-law distribution of the volume fraction of the constituents. The nonlinear formulations are based on first-order shear deformation theory (FSDT) and the large deflection von Karman equations. In the theoretical model, the reaction of the stiffener on the plate is applied partly by means of body forces in the plate equilibrium equations. The force interaction is complemented with a set of plate–stiffener displacement compatibility equations. The dynamic relaxation (DR) method combined with the finite difference discretization technique is employed to solve the equilibrium equations. To verify the present solution, several examples are analyzed for linear/nonlinear bending of FG/isotropic circular plates with different boundary conditions. A detailed parametric study is carried out to investigate the influences of the material grading index, thickness-to-radius ratios, temperature dependency of material, temperature rise, stiffener depth, stiffener position and boundary conditions. Moreover, some linear and nonlinear analyses with different thickness-to-radius ratios are carried out to consider the effect of nonlinearity on the results.