Dynamic Stress Analysis of Multisegment Curved Pipes Subjected to the Passage of an In-Line Inspection Tool

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 a preventive examination method widely used to monitor the degradation of pipelines. The passage of an ILI tool through a segment of a pipeline with loose boundary condition can generate significant dynamic stress within the pipe. When pipelines pass through excavated sites, bridges, water, and bog, or have free-span segments, they are at a greater risk of dynamic stress. This research aims to study the effects of passing an ILI tool through pipelines consisting of straight and curved segments. A three-dimensionial finite element (FE) model based on the Timoshenko beam theory is developed to model the vibration response of curved pipes during the passage of an ILI tool. Lab-scale experiments are performed to verify the simulation results of the developed FE model. The developed model is further verified through the FE analysis performed in abaqus™ implicit. A comparison of the simulation and experimental results shows that the proposed FE model effectively and accurately predicts the dynamic stress and dynamic displacements of multisegment pipes during the passage of an ILI tool.