Interaction behavior between outer pipe and liner within offshore lined pipeline under axial compression

摘要

When transmitting highly corrosive offshore hydrocarbons, one economical approach is lining internally a thin corrosion resistance alloy (CRA) layer within an ordinary carbon steel pipe. Most commonly the liner is mechanically bonded to the outer pipe by mechanical expansion. The lined pipe is expected to make optimize usage of the two types of materials, providing significant corrosion and structural resistance. This study investigates full history interaction behaviors between the outer pipe and liner and the structural behaviors of the lined pipe under axial compression, through finite element analysis (FEA). Comprehensive finite element (FE) models are developed, where the manufacturing process, the non-linear material properties of stainless steel and the interactions between the constituent components are considered. The numerically determined failure modes, load-deformation histories and ultimate strengths are compared with those from tests. The interaction stress and axial loading histories of the specimen under axial compressions are studied, where the internal content pressure and external hydrostatic pressures are considered simultaneously. Confinement factor is suggested to ensure the structural reliability of the liner in engineering practice. Parametric studies are conducted to study the effects of the outer pipe strength, liner strength, outer pipe thickness and liner thickness on the structural behaviors of the axially loaded lined pipes.