Stress analysis on various crack sizes with internal pressure and bending on a corroded pipe
Yew, Jia Jun
Date of Issue2016-05-26
School of Mechanical and Aerospace Engineering
Due to the increase usage of offshore pipelines, there will also be an increase in pipeline defects. Corrosion crack defect is one of them. In this report, with the use of Abaqus CAE software, the author will aim to study the stress behaviors of corrosion pipelines with various crack sizes ranging from crack ratio 1 to 3 and also inverse crack ratio of 2 and 3. The pipes will be subjected to pure internal pressure, pure bending and finally, combination of both internal pressure and bending. The pipe used will be API 5L X65 high strength steel pipe. Before the start of running simulations for the above models, a recognizable model has to be used for practical usage. The author has chosen DNV-RP-F101. This DNV model combines 2 corrosions into a single corrosion. The author will create a similar model using Abaqus and it will be used as a base model for all simulations. For internal pressure models, the author will study the Von Mises stress behaviors in which the pipe is subjected to multi-axial loadings namely the radial stress, the axial stress and the hoop stress. The Von Mises stress for the model will be compared to theoretical Von Mises stress and further analysis will be performed should there be any differences in the comparison. For pure bending models and also combine loading models, the author will study the crack tip opening displacement against a global strain of 3%. The behaviors in how the elements are moving will also be looked into.
Final Year Project (FYP)
Nanyang Technological University