Pipe defect assessment made by strainbased

Abstract

STRAIN-BASED DESIGN (SBD) is preferred for situations where the loading of a pipeline is due to forces other than the internal pressure and produce large stress and strain in the pipe wall.STRAIN-BASED DESIGN (SBD) is preferred for situations where the loading of a pipeline is due to forces other than the internal pressure and produce large stress and strain in the pipe wall.Under constraint conditions due to the presence of defect, tensile strains are increased due to stress concentration and the critical strain is reduced due to stress triaxiality. Such cases can be considered in design using Defect Assessment Procedures (DAP). This paper presents an extensive review of SBD methods used for pipe defect assessment as: 1. critical global strain as a criterion for pipe defect assessment; 2. critical local strain as a criterion for pipe defect assessment; 3. strain intensity factor as a criterion for pipe defect assessment; 4. notch ductility factor (NDF); 5. strain-based design based on J integral; 6. strain-based design based on CTOD. This presentation follows a rapid description of the mechanism of ductile failure, the influence of triaxiality, and loading mode through Lode angle.