Time-dependent creep analysis of rotating ferritic steel disk using Taylor series and Prandtl-Reuss relation

In this article, initial thermo-elastic and time-dependent creep evolution response of rotating ferritic steel disk (1/2 Cr, 1/2 Mo, 1/4 V) is carried out using a long-term creep constitutive equation. The material creep properties are defined by the Theta projection concept based on experimental results previously conducted on ferritic steel. Loading is an inertia body force due to rotation and a constant temperature field throughout the disk. The equilibrium equation, stress-strain and strain-displacement relations are employed to obtain a constitutive differential equation containing variable and time-dependent coefficients. To achieve history of stresses, displacement and creep strains, a numerical procedure using Taylor series and Prandtl-Reuss relation is utilized offering radial, circumferential and effective stresses and strains histories. The effect of angular velocity on creep stresses and displacements after 20 years are also reported. It is observed that a considerable redistribution occurs for stresses and strains. It is also found that an increasing rate happens for stresses and strains which must be considered for the safe design of ferritic steel disks. Moreover, increasing angular velocity raises the effective, radial, and circumferential stresses. To validate the solution approach, a composite disk was considered and its thermo-elastic and time-dependent creep behaviors were achieved. An exceptionally good agreement was found between the results obtained in this current study and the results available in the literature. (C) 2013 Elsevier Ltd. All rights reserved.