Modeling creep in a variable thickness rotating FGM disc under varying thermal gradient

Abstract

Purpose – The purpose of this paper is to investigate steady state creep behavior of a functionally graded rotating disc under varying thermal gradient (TG). Design/methodology/approach – The steady state creep in a rotating FGM disc with linearly varying thickness has been investigated by using von-Mises yield criterion. The disc under investigation is assumed to be made of FGM containing non-linear distribution of silicon carbide particle (SiCp) in a matrix of pure aluminum along the radial distance. The creep behavior of the FGM composite disc is described by threshold stress-based law. The stresses and strain rates in the FGM disc have been estimated for different kinds of TG. Findings – The results indicate that when the FGM disc is subjected to a radial TG, with temperature increasing with increasing radius, the radial stress in the disc increases over the entire disc but the tangential and effective stresses increase near the inner radius and decrease toward the outer radius. The imposition of such a radial TG in the FGM disc leads to significant reduction in the radial and tangential strain rates. With the increase in magnitude of TG in the FGM disc, the inhomogeneity in creep stresses increases but the inhomogeneity in strain rates decreases significantly, thereby reducing the chances of distortion in the FGM disc. Originality/value – The creep strain rates in rotating FGM disc could be significantly reduced when the disc is subjected to a radial TG, with temperature increasing with increasing radius.