The present study proposes a new burst capacity model for corroded oil and gas pipelines based on extensive parametric three-dimensional (3D) elasto-plastic FEA validated by full-scale burst tests. The corrosion defect is assumed to be semi-ellipsoidal-shaped in the proposed model as it better approximates the geometry of real corrosion defects than the commonly used rectangular idealization. Based on the well-known NG-18 equation for evaluating the burst capacity of corroded pipelines, the proposed model takes into account the beneficial effect of the defect width on the burst capacity and employs a new Folias factor that depends on both the defect depth and length. The flow stress in the proposed model is defined as a function of the strain hardening exponent and ultimate tensile strength of the pipe steel based on the analytical solution of the burst capacity of defect-free pipes. The accuracy of the proposed model is validated using extensive parametric FEA and shown to be higher than those of six well-known NG-18-family models, i.e. the B31G, B31G Modified, CSA, DNV, RSTRENG and SHELL92 and a model recently proposed by Sun et al.

本研究提出了一种基于广泛参数化三维（3D）弹塑性有限元分析的，经过全面爆破试验验证的，腐蚀的油气管道爆破容量模型。在提出的模型中，假定腐蚀缺陷为半椭圆形，因为它比通常使用的矩形理想化方法更好地近似了实际腐蚀缺陷的几何形状。基于评估腐蚀管道破裂能力的著名NG-18方程，提出的模型考虑了缺陷宽度对破裂能力的有益影响，并采用了新的Folias因子，该因子既取决于缺陷深度，又取决于缺陷长度。基于无缺陷管的破裂能力的解析解，所提出的模型中的流应力被定义为管钢的应变硬化指数和极限抗拉强度的函数。使用广泛的参数FEA验证了所提出模型的准确性，并显示出比六个著名的NG-18系列模型（即B31G，B31G修改版，CSA，DNV，RSTRENG和SHELL92）和最近提出的模型更高的准确性。由Sun等人撰写。