Creep deformations and stresses in thick-walled cylindrical vessels of functionally graded materials subjected to internal pressure

Steady-state creep of thick-walled cylindrical vessels made of functionally graded materials subjected to internal pressure is investigated in this paper. Taking material parameters involved in Norton’s law to be the functions of the radial coordinate, a simple and accurate method is developed from the strain rate–stress relations, Norton’s law, deformation compatibility condition and equilibrium equation of axisymmetric, plane strain problems. The proposed approach is employed to calculate stresses and creep strain rates in the thick-walled cylindrical vessels. How variations of material parameters along the radial direction affect the stresses in the vessels is examined.