Elastic analysis of internally pressurized thick-walled spherical pressure vessels of functionally graded materials

In this paper, we present an accurate method to carry out elastic analysis of thick-walled spherical pressure vessels subjected to internal pressure. Two kinds of pressure vessel are considered: one consists of two homogeneous layers near the inner and outer surfaces of the vessel and one functionally graded layer in the middle; the other consists of the functionally graded material only. The effects of Young's modulus of the outer layer, and Young's modulus and geometric size of the middle layer on the deformations and stresses in the vessels consisting of the three different layers are examined. A method to obtain an almost constant circumferential stress in the vessels consisting of the functionally graded material only is investigated.