Buckling Analysis of Corroded Pipelines under Combined Axial Force and External Pressure

Affected by a complex environment, corrosion is a common defect in steel pipelines. Moreover, steel pipelines are subjected to large axial forces during their installation and operation. Corroded deep-sea steel pipelines are prone to local buckling under complex loads. Therefore, in view of this problem, the collapse response of corroded steel pipelines under the combined axial force and external pressure is analyzed in detail. First, a formula for evaluating the collapse pressure of corroded steel pipelines under external pressure and axial force is proposed. Then, the factors affecting the collapse pressure of the steel pipeline are parameterized by using the finite element method. The accuracy of the finite element model is proved by collapse tests of the corroded steel pipeline. As shown in finite element results, the diameter-to-thickness ratio, initial ovality and corrosion defect size have significant effects on the buckling response of a steel pipeline. The collapse pressure of the steel pipeline decreases as the axial force increases. Finally, based on the finite element simulation results, the parameter variables in the evaluation formula are obtained.