Pipe-in-pipe (PIP) repair system has been acknowledged as an efficient and advanced repairing technology in the piping industry. While in service, a gas pipeline with a PIP repair system must withstand both lateral deformation and fatigue due to static and repetitive surface loads from vehicular traffic. This phenomenon creates a bottleneck in the design phase of a new PIP repair system for circumferentially cracked host pipes, as well as the estimation of bending deformation, strength, and fatigue crack initiation life, because it is costly and time-consuming. Therefore, effects of static and cyclic loads from vehicular traffic experienced by PIP system with circumferential crack and the selection of the most appropriate material properties and geometric properties is an issue that must be thoroughly explored in an effective and efficient manner.
This project aims to investigate analytically and numerically the behaviour of a PIP system with circumferential crack subjected to static and high cyclic surface loads from vehicular traffic. A simplified theoretical model using fibre model analysis (FMA) will be developed to describe the load-deflection behaviour, bending stress and strain behaviour of a host pipe with different circumferential crack widths and repaired with either thermoplastic, composites, or metallic PIP systems. The developed model will then be extended to predict the fatigue crack initiation life of a host pipe and the PIP systems. Finite element analysis (FEA) will also be implemented through Ansys software to simulate the lateral deformation and high cycle flexural fatigue behaviour of the PIP system. The FEA results will then be used to validate the FMA results. Parametric study will then be conducted to examine the effect on different parameters including material properties, geometric properties on flexural fatigue of circumferentially cracked gas pipeline with PIP repair system. The findings of this study will be beneficial in developing design specifications for PIP repair system under flexural fatigue.
For more information, please contact the Graduate Research School.