Finite Element Analyses of Burst Capacities of Pipelines Containing Pinhole-in-Corrosion Defects

Abstract This study investigates the burst capacity of pipelines containing pinhole-in-corrosion (PIC) defects through elastoplastic three-dimensional finite element analyses (FEA) and quantify the extent to which the burst capacity of the PIC defect is affected by sizes of the corresponding pinhole and general corrosion anomaly and the relative position of the pinhole within the corrosion anomaly. The PIC defect in this study is idealized as a cylindrical-shaped pinhole located within a cuboidal-shaped general corrosion anomaly. Results of extensive parametric FEA reveal that, in general, the burst capacity decreases as the pinhole depth increases; however, the bust capacity is insensitive to the diameter the pinhole. The location of the pinhole is found to be a significant factor, with pinholes closer to the edge of the general corrosion having a smaller impact on the burst capacity, while a pinhole at the center of the general corrosion can greatly impact the burst capacity. The pinhole location effect is explained by considering the impact of the bulging effect on the burst capacity of PIC. The outcomes of the study provide the basis for developing an accurate, practical burst capacity model for pipelines containing PIC defects.