Amir hoessin yosefi - Islamic azad university Shahin shahr branch–civil engineering
E Mokhtari - Islamic azad university Shahin shahr branch–civil engineering

Based on tree-order shear deformation theory and von Karman-type of kinematic nonlinearity, this paper investigates nonlinear mechanical and thermal buckling analysis of functionally graded (FG) cylindrical shells with various boundary conditions. Material properties of the constituent components of the FG shell are assumed to vary continuously according to the simple powerlaw and Mori-Tanaka distributions along the thickness direction. In order to find the critical buckling load,the axial compressive load and thermal gradient are applied to the shell incrementally so that in each load step the incremental form of governing equations are solved by newmark method combined with the finite element (FE) discretization technique.The critical mechanical buckling load is determined based on compressive load–displacement curve by adding the incremental displacements in each load step to the displacements obtained from the previous ones. The results reveal that for the higher ratios of radius-to-thickness there are not any significant difference between the results for various range of length-to-radius ratios and grading indices. It is also observed that at high radius-to-thickness ratios, not a major difference of critical thermal load isidentified between clamped and simply supported boundary conditions

Newmark -FEM method-cylindrical shell