DESIGN AND MODELLING OF PITTING CORROSION ON SUBSEA PIPELINE IN SOUTH CHINA SEA WITH FINITE ELEMENT METHOD

• Main Author: Salsabila, Nindha
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84965
• Institution: Institut Teknologi Bandung

Pitting corrosion is a structural problem that affects the integrity of subsea pipelines and often occurs. This study conducted a subsea pipeline design and analysis of subsea pipelines that experienced pitting corrosion due to combined loads from internal pressure and bending moment with variations in bending stress capacity of the intact pipe of 20%, 40%, 60%, and 80% of yield stress, pitting depth of 25% and 50% of the steel pipe thickness, and the location of the corroded area (in the tensile and compressive parts of the pipe due to bending). Pitting corrosion analysis will be carried out using the finite element method for static analysis with a general static solver and elastic-plastic material for Grade X65 pipes. From the results of the uniform pitting corrosion analysis, it was found that the bending stress capacity of the intact pipe, pitting depth, and corrosion area had an effect. The greater the bending stress capacity, the percentage difference in value between the intact pipe and the corroded pipe decreased with an average ratio of around 2.95. With each additional pitting depth, the Von-Mises Stress value for the upper corroded pipe increased by 3.24%-10.48%. Meanwhile, the Von-Mises Stress value for the lower corroded pipe increased by 1.34%-27.71%. The Von-Mises Stress value of the corrosion pipe for the upper 180o area was approximately 0.53%-18.30% greater than the lower 180o corrosion area because the corrosion area experienced pressure from the bending moment.