Yielding of Radially Pressurized Functionally Graded Long Tubes Based on Von Mises Criterion

The elastic behaviour of functionally graded long tubes with axially constrained ends subject to either internal or external pressure is investigated analytically. the modulus of elasticity and the yield limit of the tube material are assumed to vary radially in nonlinear forms. making use of von mises yield criterion, the effect of grading parameters on the yielding behavior of the tube is investigated and it is observed that for both pressure cases, the plastic flow may commence at the inner surface, at the outer surface or simultaneously at both surfaces depending on the functionally grading parameters.