Elastic-plastic buckling of pipes with asymmetric dual corrosion defects subject to external pressure

In the deep-sea environment, pipelines are prone to buckling instability under the coupling effect of hydrostatic pressure and corrosion defects. This instability phenomenon is affected by the pipe dimensions, material parameters and corrosion defects. Based on the shell buckling theory, a semi-analytical method is proposed to analyze the elastoplastic buckling response of the pipe with dual corrosion defects. The buckling pressure of the pipe can be solved by the characteristic equation numerically. Then, the results of semi-analytical approach are in good agreement with those of experimental tests and FE analysis, which verifies the accuracy of the approach. The effects of geometric dimensions, material parameters, corrosion defect depth and angle on the buckling pressure of the pipe are analyzed in details. In addition, based on the FE model, the collapse mode and the post buckling response of the pipe with asymmetric dual corrosion defects are considered. The application scope of the semi-analytical approach for pipes with different defect lengths and initial ovality is analyzed. Finally, the semi-analytical approach is extended for pipes with multiple corrosion defects.

Automated summary

By employing a semi-analytical method based on shell buckling theory, this study analyzed the elastoplastic buckling response and pressure of pipes with dual corrosion defects. The accuracy of the approach was verified through comparison with experimental tests and FE analysis, and various factors affecting the buckling pressure of pipes were thoroughly investigated. Additionally, the scope of application for different defect lengths and initial ovality of pipes was considered, and the method was extended to pipes with multiple corrosion defects.