Buckle propagation of offshore pipelines under external pressure: Fid-Bau Portal

Buckle propagation of offshore pipelines under external pressure

Gong, Shunfeng / Sun, Bin / Bao, Sheng / Bai, Yong

Abstract Accidental damage of offshore pipelines in the form of local buckles induced by excessive bending deformation during deepwater installation may severely lead to local collapse of the tube and consequent buckle propagation along the pipeline. The present paper describes experimental and numerical research conducted to predict the magnitude of buckle propagation pressure of offshore pipelines under external pressure. The experiments of buckle propagation for pipe specimens with different initial geometric imperfections using 316 grade stainless steel tubes are carried out under quasi-static steady-state conditions in a sealed hyperbaric chamber. The stress–strain characteristics in the axial tensile test are measured for the tube material, and then used to numerically calculate the buckle propagation pressure of the pipe. The comparisons between experimental and numerical results are conducted to establish the precise numerical simulation technique. Based upon experimental and extensive numerical results, a more reasonable empirical formula for buckle propagation pressure of offshore pipeline with various values of diameter-to-thickness ratio as well as different strain hardening modulus and yield stress is proposed.

Highlights ► Numerical technique offers a good prediction of the buckle propagation pressure. ► The material property has an important effect on the buckle propagation pressure. ► The paramount influencing factors are strain hardening modulus and yield stress. ► A more reasonable empirical formula for buckle propagation pressure is proposed.