Comparison of plane-stress, generalized-plane-strain and 3D FEM elastic-plastic analyses of thick-walled cylinders subjected to radial thermal gradient

- Plane-strain analysis of strain-hardening thick cylinder is carried out.
- Plane-stress and -strain analyses are compared with 3D FEM simulations.
- The validity of the plane-stress and -strain assumptions is assessed.

In many industrial applications, thick-walled cylindrical components are subjected to high pressure and/or temperature. During the operation the cylinder wall may undergo elastic-plastic deformation. This paper presents plane-stress and plane-strain thermo-elastic-plastic stress analyses of thick-walled cylinders subjected to a radial thermal gradient. A three-dimensional finite element method (3D FEM) analysis of the thermo-elastic-plastic stresses in thick-walled cylinder is also carried out. The 3D FEM results are compared with the analytical plane stress and the generalized plane strain analyses in order to study the validity of these models on the basis of length to wall-thickness ratio of cylinders. The plane stress and generalized plane strain analyses are based on the Tresca yield criterion and associated flow rule. The strain hardening behavior of the material of the cylinder is taken into account. It is observed that for the length to wall thickness ratio of more than 6, the generalized plane strain analysis can provide sufficiently accurate results. Similarly, for the length to wall thickness ratio of less than 0.5, plane stress analysis can be used. When the length to wall thickness ratio is more than 0.5 but less than 6, a three-dimensional analysis is needed.