Oblique nozzle loaded by the torque moment–stress state in the cylindrical shells on the pressure vessel

Abstract

Influence of local loads on the stress state of the shell appears as the consequence of pressure, external forces, and moment influence. Loads which act directly upon the shell surface or the parts (nozzles) connected to the shell appear in their proximity, especially in the welded joint influence zones. The influence of the torque moment affecting the free end of a slanted branch on the pressure vessel cylindrical shell is considered in this article. The stress on the cylindrical shell was analysed on 245 models of different geometrical characteristics. Stress calculated by applying the finite element method was classified by maximum stress criteria. For every considered model, maximum stress envelope has been prepared. The regressive analysis enabled the determination of correlation functions, which allow calculation of stress maximum values on the cylindrical shell according to which the shell dimensions may be determined. Result analysis shows that the percentual error is within limits as follows: from −13.4 per cent to +12.7 per cent.