Bending response and buckling of dented mechanically lined pipes manufactured by elastic vs. plastic hydraulic expansion
Year: 2026
Type: article
Abstract: Mechanically lined pipes (MLPs), combining a carbon steel carrier with a corrosion-resistant alloy liner, offer an economical solution for subsea hydrocarbon transportation. Severe bending arises during reel-lay installation and may also develop in service through lateral buckling, while local dents caused by third-party impacts further compromise the structural capacity. This study investigates the bending response of dented MLPs fabricated through plastic hydraulic expansion, in comparison with the conventional elastic expansion route. A sequentially coupled finite element framework, in which an updated Voce–Chaboche (UVC) constitutive model captures the yield-plateau behavior of the carbon steel carrier, transfers the manufacturing-induced stress state through the subsequent indentation and bending analyses. Three plastically manufactured specimens—one intact and two with controlled dents of 5%D and 7.5%D—are tested under pure bending, and the numerical model is validated against the measurements. Finally, a parametric analysis is conducted on full-scale pipelines to quantify the effects of the pipe diameter and the equivalent plastic strain (PEEQ) of the carrier pipe. For the specific material, geometry, and dent configuration analyzed, the transition from elastic to plastic expansion increases the critical curvature of the dented pipe by 38%, whereas the response is nearly insensitive to the PEEQ magnitude beyond initial yielding.
Source: Marine Structures
Institutions: Tianjin University, Universidade Federal do Rio de Janeiro
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,320
OpenAlex ID: W7221445928