Collapse behaviour of double-layer pipes: A review

Abstract Pipes serve as crucial conduits for fluid transportation across diverse industrial sectors, necessitating a thorough understanding of their structural properties and performance under varying conditions. This study explores the resilience of underwater double-layer pipes, comprising inner and outer layers separated by an annulus that usually used in deep water application such as OTEC and gas and oil transport, against collapse induced by bending moment loads or external pressure. The investigation encompasses a comprehensive review of relevant literature and examines different configurations of DLP. The analysis reveals that key factors influencing the buckling capacity under pure bending loads include pipe length, core thickness ratio, and core stiffness. Under hydrostatic pressure, collapse behavior is influenced by the radius-to-thickness ratio and the ratio of the core thickness to outer and inner layer thicknesses. Furthermore, the collapse mechanism of the double layer pipe is analyzed. The study underscores the importance of addressing such structural nuances in design and operational considerations.