Abstract
Pipelines are susceptible to degradation over time due to different types of defects caused by environmental and loading conditions. In-line inspection (ILI) is an assessment method widely used for pipeline degradation monitoring. The passage of an ILI tool through a section of a pipeline can generate significant dynamic stress within the pipe. Pipelines can pass through water, muskeg, excavated, or free-span sections, which provide less support. These partially-supported pipe segments are more prone to dynamic stress with the passage of an ILI tool. This research aims to study the effects of passing an ILI tool through multiple pipe bends in series constituted of both straight and curved segments. The passage of an ILI tool can excite a pipeline close to its natural frequencies where the amplitude of vibrations and consequently the dynamic stress increase rapidly. A 3D finite element (FE) model based on the Timoshenko beam theory is developed to model curved pipes subject to the passage of an ILI tool. Lab-scale experiments are performed to verify the results of the developed FE model. The developed model is further verified using finite element analysis (FEA) performed in ABAQUS™ Implicit. A comparison of the simulation and experimental results shows that the proposed model predicts the dynamic stress and displacements of multi-section pipe segments during the passage of an ILI tool effectively and accurately.