A Design Equation for the Stress Concentration Factor of an Oblate Ellipsoidal Cavity

Abstract

The stress concentration factor (SCF) of an oblate ellipsoidal cavity in an isotropic material subjected to a uniform normal stress at infinity perpendicular to the equator of the cavity is determined by the equivalent inclusion method. Numerical results are obtained for general cases; particularly, explicit and exact results are obtained for cases of strongly oblate cavities. To extend the range of validity for these cases, a two-dimensional model is developed for finding the correction terms and a simple equation for the SCF of an oblate ellipsoidal cavity is thus obtained. The accuracy of the equation is probed and it is shown that the proposed formula is sufficiently accurate for design purposes.