Stress concentration factor based design curves for cylinder-cylinder connections in pressure vessels

The results of the parametric analysis of the cylinder-cylinder intersections in pressure vessels, performed in both elastic and plastic regions, are discussed in this study. Besides, the outcomes that contribute to the development of classical solutions in the literature are addressed as design curves depending on stress concentration factors (SCF). To begin with, the maximum stresses for cylinder-cylinder connections were calculated by finite element analysis and SCF values were obtained. In these calculations, external local loads acting on the nozzle centre and internal pressure are the main variables for loading conditions. Following that, different parametric approaches and loading conditions are presented to develop design curves for cylinder/cylinder connections by changing the main geometric parameters, such as cylinder and nozzle radii, and their thicknesses. A new approach is presented using these new curves thus allowing industrial designers to calculate maximum nozzle stresses without the need to undertake a thorough finite element analysis.