Assessment of creep in composite disc having exponential, hyperbolic and uniform thickness profiles

Abstract

Analysis has been carried out to model second stage creep in a composite (Al-SiCp) disc rotating at high speed under elevated temperature. The model has been developed for various kinds of disc thickness profiles, viz. exponential, hyperbolic and constant, with the same total volume. The impact of varying the disc geometry has been assessed through the stresses and rates of creep induced strains in different discs. The results indicate that the stresses and strain rates in composite disc with exponential thickness variation are the lowest for similar operating conditions. The creep response of exponential disc is observed to further improve when its thickness gradient is increased, achieved by increasing the thickness near the inner and decreasing towards the outer disc radius, without altering the average disc thickness. The use of steeper thickness profile could help in reducing the possibility of creep induced deformations in the rotating disc.