Subsea pipelines transport offshore petrochemical resources. Such pipelines undergo lateral global buckling deformations owing to the high temperatures and pressures during operation. The large lateral deformation generated in a lateral global buckling process causes the cross-section of the deformed pipeline to bend plastically, threatening the integrity of the pipeline system. The value of the plastic strain is a key index for assessing the safety of deep-sea pipelines. This study analysed the distribution and development of a plastic strain during a lateral global buckling process using the finite element method, highlighting the decisive role of the initial imperfection on the location of the plastic strain, and the impacts of three types of influential parameters on the value of the plastic strain. Based on a large number of simulation results, fitting equations were proposed for predicting the value of the plastic strain according to the values of the influential parameters. Validations of the fitting equations were also conducted; the relative deviation between the predicted value and finite element analysis results is less than ±8 % for predicting a typical compressive strain, and less than ±10 % for predicting a typical tensile strain.

海底管道运输近海石化资源。由于操作期间的高温和高压，这样的管道经历了横向的整体屈曲变形。在横向整体屈曲过程中产生的大横向变形会导致变形的管道的横截面发生塑性弯曲，从而威胁到管道系统的完整性。塑性应变的值是评估深海管道安全性的关键指标。这项研究使用有限元方法分析了横向整体屈曲过程中塑性应变的分布和发展，强调了初始缺陷对塑性应变位置的决定性作用，以及三种类型的影响参数对塑性应变的影响。塑性应变的值。基于大量的仿真结果，提出了拟合方程，根据影响参数的值预测塑性应变的值。还对拟合方程进行了验证；预测值与有限元分析结果之间的相对偏差在预测典型压缩应变时小于±8％，在预测典型拉伸应变时小于±10％。