Modeling Steady State Creep Behavior of Functionally Graded Thick Cylinder in the Presence of Residual Stress

The steady state creep behavior in a functionally graded thick composite cylinder subjected to internal pressure has been investigated in the presence of residual stress. Hoffman's yield criterion is used, to describe the yielding of the cylinder material in order to account for residual stress. The results obtained are compared with a similar cylinder but yielding according to von Mises criterion. The cylinder is made of functionally graded material containing linearly varying silicon carbide whiskers in a matrix of 6061aluminum. The study shows that in the presence of residual stress in composite cylinder the radial stress decreases slightly over the entire cylinder, whereas the tangential and axial stresses increase significantly near the inner radius but show considerable decrease towards the outer radius. The effective stress in the cylinder increases in the presence of residual stress and the maximum increase near the outer radius. The study also reveals that the creep rates are strongly influenced by the presence of residual stress in the cylinder material.