Modelling of creep behaviour of a rotating disc in the presence of load and variable thickness by using seth transition theory

The purpose of this paper is to present study of creep behaviour of a rotating disc in the presence of load and thickness by using Seth's transition theory. It has been observed that a flat rotating disc made of compressible as well as incompressible material with load E-1 = 10, increases the possibility of fracture at the bore. It Is also shown that a rotating disc of incompressible material and thickness that increases radially experiences higher creep rates at the internal surface in comparison to a disc of compressible material. The model proposed in this paper is used in mechanical and electronic devices. They have extensive practical engineering applications such as in steam and gas turbines, turbo generators, flywheel of internal combustion engines, turbojet engines, reciprocating engines, centrifugal compressors and brake discs

Modelling of creep behaviour of a rotating disc in the presence of load and variable thickness by using seth transition theory

The purpose of this paper is to present study of creep behaviour of a rotating disc in the presence of load and thickness by using Seth's transition theory. It has been observed that a flat rotating disc made of compressible as well as incompressible material with load E-1 = 10, increases the possibility of fracture at the bore. It Is also shown that a rotating disc of incompressible material and thickness that increases radially experiences higher creep rates at the internal surface in comparison to a disc of compressible material. The model proposed in this paper is used in mechanical and electronic devices. They have extensive practical engineering applications such as in steam and gas turbines, turbo generators, flywheel of internal combustion engines, turbojet engines, reciprocating engines, centrifugal compressors and brake discs

Thermal effect on the creep in a rotating disc by using Sherby’s law

The effect of imposing linear thermal gradient on the steady state creep behavior of a rotating functionally graded Al-SiCp disc is investigated in the present study by using Sherby’s law. Mathematical model to describe steady state creep behavior in rotating disc made of isotropic Al-SiC composite in presence of linear thermal gradient in the radial direction has been formulated. The distributions of stresses and strain rates have been obtained. The creep response of a composite disc with uniform temperature has also been computed for comparison with the results obtained for thermally graded discs. The creep rates in a rotating thermally graded disc can be significantly reduced in presence of thermal gradients

Elastic-plastic transition on rotating spherical shells in dependence of compressibility

The purpose of this paper is to establish the mathematical model on the elastic-plastic transitions occurring in the rotating spherical shells based on compressibility of materials. The paper investigates the elastic-plastic stresses and angular speed required to start yielding in rotating shells for compressible and incompressible materials. The paper is based on the non-linear transition theory of elastic-plastic shells given by B.R. Seth. The elastic-plastic transition obtained is treated as an asymptotic phenomenon at critical points & the solution obtained at these points generates stresses. The solution obtained does not require the use of semi-empirical yield condition like Tresca or Von Mises or other certain laws. Results are obtained numerically and depicted graphically. It has been observed that Rotating shells made of the incompressible material are on the safer side of the design as compared to rotating shells made of compressible material. The effect of density variation has been discussed numerically on the stresses. With the effect of density variation parameter, rotating spherical shells start yielding at the internal surface with the lower values of the angular speed for incompressible/compressible materials