Stress Concentration in a Pipeline with Surface Hollow in the Form of a Semiellipsoid of Revolution

For the analysis of stress concentration in the region of a local hollow in a pipeline in the form of a semiellipsoid of revolution, we use a computational model based on the three-dimensional problem of a layer subjected to biaxial tension. The numerical analysis of this problem is performed with the help of a semianalytic finite-element method by using bilinear quadrangular elements. We deduce an engineering formula for the evaluation of the maximum stress intensity factors.