Equivalent stress in a pressure vessel head with a nozzle

The paper is devoted to analysis of a dished head of a pressure vessel subject to internal uniform pressure and provided with a nozzle. A short survey of optimal design of the pressure vessel and its head is presented. The vessel head of a selected optimized shape is then completed by a nozzle, and the equivalent stress pattern is observed and recorded. The axis of symmetry of the nozzle is parallel to that of the vessel. The nozzle is placed in various distances from the axis of symmetry of the vessel. The dimensionless distance $e$ between both axes varies from 0 (i.e. axisymmetric location) up to 0.8 (assuming that the radius of cylindrical part of the vessel is equal to 1). Results of numerical calculation are presented in plots and figures.