Nonlinear thermal stress analysis of functionally graded spherical pressure vessels

Abstract

In this study, nonlinear analysis of functionally graded spherical pressure vessels composed of metal/ceramic mixture for both high strength and high thermal resistance is discussed. The originality of this study is to think that all material properties change with temperature as well as thickness by using a realistic and physically meaningful graded material model with the Halpin–Tsai homogenization scheme. These conditions results in nonlinear differential equation that may not be solved with conventional methods. The nonlinear temperature and stress distributions of the functionally graded sphere under the thermo-mechanical loads are determined by using the pseudospectral Chebyshev method. Some stress results based on the assumptions of temperature-dependencies and temperature-independencies of the material properties are derived and effects of various parameters on the thermoelasticity are studied. Besides, elastic limits based on the von Mises’ yield criterion are also discussed according to whether the material properties are dependent on temperature or not. Benchmark linear examples are used to check the accuracy of the method. The nonlinear solutions are verified with the finite element method using the ANSYS package program.