Study on Residual Strength of Pipe with Single Hemisphere Bottom Defect Using FEM Analysis

Abstract

The stress and strain condition of the corroded line pipe with single hemisphere bottom defect under deferent inner pressure were analyzed by the Finite Element Methods (FEM) in this paper; At the same time, the residual strength models for the corroded pipe were established based on both the Von Mises equivalent stress and the Von Mises equivalent strain of the finite unit on the defect local zone respectively, the residual strength was decreased with the defect size (d/t) linearly. This way, the residual strength for the corroded pipe with a given defect size (d/t) could be conducted by using the model properly, which could help the owner make a decision when happened to the same defect in the operation. The analysis results shown that the residual strength calculation should choose based on stress when the defect depth (d/t) was less than 0.5, or else choose based on the strain when defect depth (d/t) was exceeds 0.5.

Finite element study on residual internal pressure strength of corroded oil pipes and prediction method for remaining life

“…However, these methods have some limitations in describing the precise failure pressure, and each has its specific scope of application (Fu and Batte, 1999;Choi et al, 2016). The finite element method can consider the nonlinearity, elasticity and plasticity of the corrosion damaged pipeline (Sun et al, 2015;Yang et al, 2011;Abdalla Filho et al, 2010;Mohd et al, 2015;Chen et al, 2015a), and it can get better evaluation results. Chouchaoui and Pick (1996), Chouchaoui and Pick (1996), Bin and Kirkwood (1995) and Bin and Kirkwood (1995) in Canada have all performed non-linear finite element analysis on corroded pipes and conducted experimental verification.…”