Fatigue life assessment of damaged pipelines under cyclic internal pressure: Pipelines with longitudinal and transverse plain dents

Abstract

This ongoing work aims to refine a methodology for fatigue life assessment of dented steel pipelines under cyclic internal pressure. A numerical model is developed to obtain stress concentration factors on dented pipes under internal pressure. A comprehensive parametric study is accomplished and analytical expressions to estimate stress concentration factors for spherical, longitudinal and transverse plain dents as a function of selected geometric parameters are developed. The proposed fatigue assessment methodology is validated from fatigue test results. Here, the analytical expressions are refined to include a more complete dent geometry definition for transverse, longitudinal and short longitudinal dents. © 2014 Elsevier Ltd. All rights reserved.