Linear buckling behavior of power and sigmoid SF.G.FG cylindrical shells under axial compression or lateral pressure: a comparative study

Purpose – This study aims to investigate the linear buckling behavior of functionally graded cylindrical shells under axial compression or lateral pressure. The shells are composed of functionally graded materials (FGMs), with through-the-thickness property variation defined by power-law (P-SF.G.M.FGM) or a sigmoid-law (S-SF.G.M.FGM) distribution. Design/methodology/approach – The governing equilibrium and stability equations for the buckling analysis are derived based on classical shell theory. To determine a critical buckling load, an approximated solution is assumed which satisfies the boundary conditions as well as the governing equations. The finite element analysis in SA.N.S.Y.S.ANSYS is also used to determine the critical buckling load. Findings – The findings indicate that P-SF.G.M.FGM shells have a critical buckling load approximately 40% higher than S-SF.G.M.FGM shells. The reason for the increment is that P-SF.G.M.FGM shells have a higher effective stiffness, especially in bending, due to the material distribution profile. The analytical approach proved to be efficient, offering reduced computational effort compared to complex finite element models. Research limitations/implications – The material is considered to be linear elastic, and the structures are free of imperfections. Originality/value – The research focuses on examining the influence of material gradation using P-SF.G.M.FGM and S-SF.G.M.FGM model. It compares the critical buckling load of shells subjected to axial compression or lateral pressure. Overall, the results highlight the significant influence of material gradation on buckling behavior and provide insights for optimizing SF.G.M.FGM shell configurations.