Creep transition in a thin rotating non-homogeneous disc

Creep stresses in a thin rotating annular disc made of non-homogeneous material have been investigated, using transition theory. As a numerical example, it has been seen that the presence of non-homogeneity having lesser value at the bore, reduces the stresses and the angular velocity required for steady state of creep as compared to the homogeneous disc; however, that having higher value at the bore than at the rim, increases the magnitude of angular velocity and creep stresses significantly, and hence increases the possibility of a fracture in the vicinity of the bore.