An analytical solution to lateral buckling control of subsea pipelines by distributed buoyancy sections

• An analytical solution for lateral buckling in the entire design region is deduced.
• RSM is adopted to improve the numerical stability and the calculation efficiency.
• The framework for buckling control using distributed buoyancy sections is presented.
• This paper performed the comparison analysis between RSM and FEA.

Lateral buckling is the primary buckling form of the subsea pipelines. A promising recent practice is to the distributed buoyancy sections to control the lateral buckling of subsea pipeline. In this study, an analytical solution is deduced for the lateral buckling of the pipeline with buoyancy sections in the entire design region. However, numerical difficulty was encountered during the solution of the design equations. To overcome this difficulty, we adopt a response surface method (RSM) for the solution of nonlinear equation system. A strategy of multi-response-surface is proposed by dividing the entire design region into several partial domains and establishing different kinds of response surfaces for each region. A framework for lateral buckling control of subsea pipelines using distributed buoyancy sections is presented. Several illustrative examples demonstrate that the proposed method has a high efficiency and accuracy in solving the problem of the lateral buckling control.