Stress concentration factors for flat endcaps

Abstract

Endcaps on pressure vessels have stress concentrations which lead to fatigue crack initiation and growth during cycling of power generating plant. Finite element analyses of actual endcaps showed a current analytical method to be inaccurate. To develop a model, the maximum non-Mises stress was calculated across a range of geometries using over 380 finite element models. A new analytical method of calculating the stress concentration factor was developed based on the ratio of the von-Mises stress in the fillet to the hoop stress in the remote vessel wall. © 2017 Engineers Australia