Effect of Disc Geometry on the Steady State Creep in a Rotating Disc Made of Functionally Graded Materials

Abstract

The steady state creep behaviour of a rotating FGM disc having linearly varying thickness has been investigated. The disc is assumed to be made of functionally graded composite containing non-linearly varying radial distribution of silicon carbide particles in a matrix of pure aluminum. The creep behaviour of the composite has been described by threshold stress based law. The effect of varying the disc thickness gradient has been analyzed on the stresses and strain rates in the FGM disc. It is observed that the radial and tangential stresses induced in the FGM disc decrease throughout with the increase in thickness gradient of the disc. The strain rates also decrease with the increase in thickness gradient of the FGM disc, with a relatively higher decrease near the inner radius. The increase in disc thickness gradient results in relatively uniform distribution of strain rates and hence reduces the chances of distortion in the disc.