Mathematical Modeling of Creep in a Functionally Graded Rotating Disc with Varying Thickness

Abstract

This study puts forward an analytical framework for the analysis of creep stresses and creep rates in the isotropic rotating non-FGM/FGM disc with uniform and varying thickness. The material parameters of creep vary along the radial distance in the disc due to varying composition, and this variation has been estimated by regression fit of the available experimental data. The creep behavior of the disc under stresses developing due to rotation has been determined following Sherby’s law. The creep response of rotating disc is expressed by threshold stress with value of stress exponent as 8. The results obtained for isotropic non-FGM/FGM constant thickness disc have been compared to those estimated for isotropic varying thickness disc with the same average particle content distributed uniformly. Overall, our results suggest that the distribution of stresses and strain rates becomes relatively more uniform in the isotropic FGM hyperbolic thickness disc. The purpose of this paper is to investigate the steady-state creep response in the isotropic non-FGM/FGM varying thickness disc with linear variation of particle distribution along the radial distance. Mathematical model to describe steady-state creep behavior in an isotropic rotating disc made of silicon carbide particulate composite has been developed. Three variations in the thickness (constant, linear, and hyperbolic) of the rotating composite non-FGM/FGM disc have been considered, while keeping average volume of all the discs is the same. The study revealed that the strain rates are the lowest and more uniform in the FGM hyperbolic thickness disc having reinforcement distributed in a linear way as compared to non-FGM/FGM discs with constant and linear thickness.