含初始缺陷海底管道外压非线性屈曲研究

摘要

随着海洋油气的开采逐步走向深水,外部静水压力成为深水海底管道的重要环境条件.含初始缺陷海底管道在外部压力的作用下,可能会发生局部屈曲,并沿轴向发生屈曲传播,造成重大损失.为了进一步探究含初始缺陷海底管道在实际工况下受到外压作用时的响应,运用数值模拟方法对海底管道在外压作用下的屈曲特性进行研究.考虑到海底管道材料非线性和几何非线性,通过非线性有限元方法对带初始缺陷管道的压溃力学特性进行了研究;基于Python参数化建模的方法,计算超过1 200个数值模型,对影响带初始缺陷管道屈曲的几何参数和材料参数进行敏感性分析;运用非线性最小二乘法拟合得到极限承载力简化计算公式,并与相关试验数据进行对比,误差小于7％.%With constantly promoting of oil and gas development from shallow water to deep sea,external pressure is a critical loading condition for subsea pipelines.The local buckling may occur for pipelines with initial defect under external pressure.The local buckling may lead to the collapse propagated simultaneously.To further explore the subsea pipeline with initial defect under external pressure being in the actual situation,the characteristic buckling under the numerical simulation methods described herein subsea pipeline which external pressure has been studied.Taking into account non-linear material and geometric nonlinear subsea pipeline,the mechanical properties of crushed paper with initial defect pipeline was studied by nonlinear finite element method,and based on Python parametric numerical modeling method,calculating over 1 200 times,to geometry and material parameters buckling of pipelines with initial defect sensitivity analysis,and the use of non-linear least squares fitting ultimate bearing capacity simplified formula,and finally with relevant experimental data were compared.