Stress Concentration Factors in Spherical Vessels with Single Oblique Nozzle

Finite element method is employed to analyze the spherical vessel intersected by an oblique cylindrical nozzle. In this survey the stress and strain distributions on acute and obtuse sides of the connection under internal pressure are studied widely although axial and moment loadings on the nozzle are also studied briefly. Stress concentration factors for a wide range of geometrical ratios in term of membrane stress in the sphere are calculated and presented. Variation of these factors with angle of obliquity of the branch is also investigated. The results are compared with measured quantities and with those mentioned in other references. It is assumed that the definition of thin shell is valid for both vessel and nozzle simultaneously and that the corners are sharp without any reinforcement. ABAQUS computer program is used in this survey.