Modeling of Creep Behavior of a Rotating Disc in the Presence of Both Composition and Thermal Gradients

Abstract

The creep behavior of a rotating disc made of isotropic composite containing varying amounts of silicon carbide in the radial direction has been investigated in the presence of a thermal gradient, also in the radial direction. The variation of silicon carbide content has been so tailored as to contain larger amounts of particles in a highly stressed region. This type of inhomogeneous material is known as Functionally Graded Material (FGM). The thermal gradient experienced by the disc is the result of braking action as estimated by FEM analysis. The creep behavior of the disc under stresses developing due to rotation has been determined following Sherby’s law and compared with that of a similar disc following Norton’s law. The difference in the distribution of stresses and strain rates in the discs does not follow any definite trend but the values are somewhat different. The presence of thermal gradient and a linear particle gradient separately or their simultaneous presence result in a significant decrease in steady state creep rates as compared to that in a composite disc with the same average particle content (20 vol %) distributed uniformly and operating under isothermal condition. Further, the study revealed that the creep behavior of a FGM disc could be significantly improved by increasing the gradient of particle distribution while keeping the same average particle content of 20 vol % silicon carbide in the disc.

Effect of Reinforcement Profile On Creep Rates in a FG Disc

“…Singh and Ray [4] investigated steady state creep in a rotating isotropic FGM disc of constant thickness by using Norton's power law. Gupta et al [3] extended the work to investigate the creep rates for a constant thickness rotating FGM disc operating under thermal gradient. Several authors investigated creep response in rotating FGM disc but using linear thickness profile [3,5].…”

“…Gupta et al [3] extended the work to investigate the creep rates for a constant thickness rotating FGM disc operating under thermal gradient. Several authors investigated creep response in rotating FGM disc but using linear thickness profile [3,5]. In the present study we have investigated effect of reinforcement profile on creep rates in rotating FGM disc.…”

“…Rotating disc is very important due to its extensive use in engineering applications [3]. Singh and Ray [4] investigated steady state creep in a rotating isotropic FGM disc of constant thickness by using Norton's power law.…”

Numerical creep analysis of FGM rotating disc with GDQ method

“…A wide area research has assigned to rotating discs because of their numerous utilizations in various industries and rotating machines such as: gas and steam turbines, pumps, turbo generators, compressors, flywheels, ship propellers and automotive braking systems (Gupta et al, 2005;Hojjati and Hassani, 2008;Singh and Ray, 2002). In most of these applications, discs have to operate at high rotational speed leading to large centrifugal forces, and in the presence of high temperatures, the materials strength can be reduced explicitly.…”

Creep Analysis of a Variable Thickness Rotating FGM Disc using Tresca Criterion

“…A rotating disc, in number of applications (as outlined earlier), is subjected to steady-state creep. In most of the studies pertaining to analysis of steadystate creep in rotating FGM disc, the disc thickness is assumed to be constant 1, [17][18][19] . Only a few studies have been undertaken to analyze steady-state creep in FGM disc of variable thickness, wherein the researchers have observed that the disc weight 20 or strain rates in the disc could be significantly reduced using varying thickness profile 21 .…”