Analytical study on lateral buckling of lined pipes under high temperature and high pressure

The use of lined or clad pipes, which have a highly corrosion-resistant material inner layer, is common in subsea pipelines. Unburied lined pipes may experience lateral buckling under high-temperature and high-pressure conditions. In this study, closed-form analytical solutions for different lateral buckling modes have been developed with the Euler-Bernoulli beam theory. The study also discusses the impact of different buckling modes on the buckled configurations and post-buckling behaviour. In addition, the buckling behaviour of the outer pipe and liner in the post-buckling process is compared. The research indicates that the length of the buckled lined pipe can't be assumed to be a fixed value in lateral buckling analysis. While different types of lateral buckling modes only affect the behaviour of lateral buckled deflection, they have little effect on the axial deformation behaviour of the lined pipe. In the post-buckling process, the axial compressive force in the wall of the liner may be higher than that of the outer pipe when the temperature is sufficiently high.