Thermo-elastic analysis of functionally graded porous thick-walled cylindrical pressure vessels with variable thickness subjected to mechanical and thermal loading by higher-order shear deformation theory

Abstract

The aim of this research is to analyze the displacements, strains, and stresses is made in the thick-walled cylindrical pressure vessels with a variable thickness subjected to mechanical and thermal loading created of functionally graded porous materials with clamped-clamped boundary conditions. Linear profile is considered for variable thickness. Initially, the governing equations of thick-walled cylindrical shells are extracted using the energy method for a non-homogeneous functionally graded porous material (FGPM) with the power law function of mechanical and thermal properties under mechanical and uniform thermal loading. In this research, by utilizing the application of higher-order shear deformation theory (HSDT) and multi-layers method (MLM), a semi-analytical solution is provided to analyze symmetrical deformations and stresses. Due to the lack of analytical solution for differential equations of the variable thickness cylindrical shell, using the multi-layers method, the variable thickness cylindrical shell is divided into fixed thick disks. Finally, the solutions of each disk are analytically obtained and sum of them are employed for the whole cylindrical shell. The material used in the cylindrical vessel is a porous ceramic-metal, with alumina (Alumina, alpha Al2O3,99.5%) for ceramic and aluminum for metal that is a novel idea for thick-walled cylindrical pressure vessels with a variable thickness. Apart from the Poisson ratio, the characteristics of the materials are believed to change following a power law function in the radial direction of the cylindrical shell. The governing equations, which make up a system of differential equations with variable coefficients, have been resolved using MLM. The research explored how high-level approximations affect different parameters, such as radial and axial displacements, stresses, and strains. To demonstrate the efficiency and precision of the MLM and accurateness of the results, a result comparison is carried out between MLM method and MAM and FEM method. To study the mechanical behavior of the cylindrical pressure shell, some numerical findings were presented, examining the impact of different amounts of non-homogeneity (gradient index), porosity, and mechanical and thermal loads on it.