Nonlinear Contact Between Pipeline's Outer Wall and Slip-on Buckle Arrestor's Inner Wall During Buckling Process

摘要

In order to theoretically study the buckle propagation of subsea pipelines with slip-on buckle arrestors,a two-dimensional ring model was set up to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between pipeline's inner walls and between pipeline's outer wall and slip-on buckle arrestor's inner wall during buckle propagation.In addition,some reverse springs are added to prevent the wall of left and right sides separating from the inner wall of slip-on buckle arrestors.Considering large deformation kinematics relations and the elastic-plastic constitutive relation of material,balance equations were established with the principle of virtual work.The variation of external pressure with respect to the cross-sectional area of pipelines was analyzed,and the lower bound of the crossover pressure of slip-on buckle arrestors was calculated based on Maxwell's energy balance method.By comparing the theoretical results with experiment and finite element numerical simulation,the theoretical method is proved to be correct and reliable.