A modified numerical calculation method of collapse pressure for thick-walled offshore pipelines. (October 2019)

• Record Type: Journal Article
• Authors: Yu, Jian-xing; Han, Meng-xue; Duan, Jing-hui; Yu, Yang; Sun, Zhen-zhou
• Is Part Of: Applied ocean research. Volume 91(2019)
• Publication Date: 2019-10
• Subjects: Collapse pressure -- Thick-walled pipes -- Shear deformation -- Manufacturing imperfections; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2019.101884
• Languages: English
• ISSNs: 0141-1187

Abstract

Highlights: Based on thick shell theory, a 2D numerical calculation method is developed. Ten experiments are conducted to verify the accuracy of numerical predictions. Collapse pressure given by DNV standard is conservative for thick-walled pipe. Collapsing of thick-walled pipe is dominated by material plastic behavior. Abstract: Considering the shear deformation and thickness stretching of large deformation, a modified numerical calculation method based on the thick shell theory is established to determine the collapse pressure of thick-walled pipes. Verification experiments are conducted on ten pipe specimens in hyperbaric chambers. The good agreement between experimental results and numerical predictions shows the validity and reliability of the new numerical calculation method. Combining DNV specification, the characteristic collapse pressure is also calculated for comparison. The difference between experimental results and DNV calculations illustrates the latter one is much conservative in predicting collapse pressure for thick-walled pipes. Sensitivity analysis on manufacturing imperfections and material properties is investigated for pipes with different D/t ratios. Thick-walled pipes are easier to be affected by initial ovality, residual stress and hardening factor. Based on the stress distribution at the moment of collapse, a novel discovery is found that the collapse pressure of thick-walled pipes is dominated by material plastic behavior.