EFFECT OF PRESSURE DIFFERENCE ON STATIONARY AND ROTATING ANISOTROPIC DISCS

The stress analysis of pressurized and rotating isotropic discs is a classical problem which can be found in literature. In a recent paper, Kookson and Sathianathan indicated that the effect of anistropy, on the stress distribution within a rotating disc, is considerable. In our proposed work, the effect of pressure on stationary and steady rotating discSis studied. The stress distribution in stationary discs, under inner and outer pressures, is analyzed for different values of anisotropic constant X= A7E71 where Ee and Er are the material elastic moduli in tangential and radial directions respectively. The effect of variable parameters, radius ratio, anisotropic constant X , pressure difference, is determined for the case of orthotropic steady rotating annular discs. Our results indicate that the effect of anisotropy, on the stress distribution within a disc, is considerable. INTRODUCTION The analysis of thin elastic annular discs is of great importance for many engineering applications such as gas-turbines, ste4mturbines, compressors, flywheels and computer stores. Hence, it is often necessary to determine their deformations and the stress distributions within thenl, A considerable amount of literature exists for the case where isotropic materials are used in fabrication of discs. However, much interest has been shown, in recent years, in the possibility of constructing discs from compos. ite materials. These materials always have some kind of anisotropy, in which the elastic modulus and the strength differ from one direction to another. Composite materials are used in such a manner that the direction of their greatest strength corresponds to the direction c& principal load acting above the device. In this way, it can be. possible to construct light weight components of optimum load carrying capacity. Cookson and Sathianathan 111 determined the stress distribution within anisotropic discs which are xotating at steady speed. They indicated that the effect of anisotropic constant X is considerable, while the effect of varying the value of Poisson's ratio ver is slight. In the present work, the stress analysis of stationary annular anisotropic discs, under the effect of internal and external pressures,is deduced. The * Col. Dr., ** Lt. Col. Dr., Dpt. of Mechanics and Elasticity, Military Technical College, Cairo, Egypt.