STRESS ANALYSIS OF FUNCTIONALLY GRADED CYLINDERS SUBJECTED TO THERMO-MECHANICAL LOADS BASED ON BERNSTEIN POLYNOMIALS

Stress analysis of thick walled functionally graded (FG) cylindrical pressure vessels subjected to uniform axisymmetric thermo-mechanical loads is presented using Bernstein polynomials. All thermal and mechanical properties except Poisson's ratio of the FG vessels vary through the thickness with arbitrary functions of the radial coordinate. Based on the thermo-elasticity theory, the first law of thermodynamics and axisymmetric assumption, the governing equations of the semi-coupled thermo-elasticity problem reduce to a set of second order boundary value problem. Galerkin method together with Bernstein polynomials is used to obtain solution for the governing equations. The presented method is simple to implement, efficient and accurate. Predictions of some special cases for which analytical results are available in the literature are used to validate the method. Comparison of the results for stress and displacement components and temperature distribution with analytical results shows excellent agreement. Furthermore, predictions for radial displacement, stresses and temperature in various cylindrical pressure vessels with different material models are presented for future references.