Session: MF-13-01 Composite and Non-Metallic Systems for Pressure Vessels and Piping

Paper Number: 105954

105954 - Evaluation of the Defect Width Effect on the Burst Pressure of a Corroded Pipeline Repaired Using Composite Materials 

To repair corroded oil and gas pipelines and ensure that the pipelines are fit for service, composite materials such as the fiber reinforced polymer (FRP) are often used to build an external sleeve that consists of fiber reinforcement in a thermoset polymer matrix. The composite materials have much lower densities but higher ultimate strengths than the pipe steel. These properties together with the ease for transportation and on-site application make composite materials appealing for the rehabilitation of corroded pipelines. The basic design approach for pipelines repaired by composites is that the hoop stress due to the pipe internal pressure at the location of a corrosion defect is transferred to the composite sleeve. Analytical methods proposed in the literature to predict the burst pressure of composite-repaired corroded (CRC) pipelines are developed by idealizing the corrosion defect to cover the full circumference of the pipe and considering the equilibrium between the internal pressure and stresses in the steel pipe and composite sleeve. In reality, the width of a corrosion defect, i.e. in the pipe circumferential direction, is typically much less than the pipe circumference. There is a lack of studies to investigate the effect of the defect width on the burst pressure of CRC pipelines and the adequacy of the existing analytical burst pressure models. In this study, the corrosion defect width effects on the burst pressure of CRC pipelines are investigated using extensive parametric elasto-plastic finite element analyses. The finite element model includes constitutive material modelling of both steel and composite and is validated using full-scale burst tests reported in the literature. The parametric analysis considers different values of the defect depths, lengths and widths, and properties of the composite to assess the effect of the defect width as a function of other parameters that affect the burst pressure. The dependency of the critical failure mechanism and burst pressure on the defect shape and size is observed based on the analysis results. A correction factor on the analytical burst pressure model is proposed to account for the defect width effect and improve the accuracy of the analytical models.

Presenting Author: Rodrigo Silva Silva-Santisteban University of Western Ontario

Presenting Author Biography: Rodrigo Silva is a Civil Engineer that specializes on analysis and design of pipelines. He is currently an MSCE candidate at Western University with research focused on the rehabilitation of pipelines using composite materials.

Authors:

Rodrigo Silva Silva-Santisteban University of Western Ontario
Wenxing Zhou University of Western Ontario