Pressure-Plus-Moment Limit-Load Analysis for a Cylindrical Shell Nozzle

Abstract

A finite element model of a nozzle in a cylindrical shell is analyzed for three cases; pressure, out-of-plane moment and combined pressure plus out-of-plane moment. The model uses three-dimensional finite elements and the analysis considers inelastic behavior at small displacements. Load versus displacement behavior is given for the three cases. Estimates of limit loads are obtained based upon extrapolation of load versus inverse displacement data curves. An interaction expression is used to show the effect of the combined loading for a case in which an internal pressure reduces the moment capability of the nozzle by 35 percent.

Finite element-based limit load of piping branch junctions under combined loadings

“…Tabone and Mallett (1987) used a three-dimensional FE model of a nozzle in a cylindrical shell with a diameter ratio of 0.65 to analyze the limit load for the case of combined pressure plus out-of-plane moment. The limit load is obtained based upon extrapolation of load versus inverse displacement data curves.…”