Adhesive-Reinforced Mechanically Lined Pipe Response Under Bending

Abstract

Abstract. Mechanically lined pipes (MLPs) are widely used in offshore oil and gas applications due to their corrosion resistance, but their thin corrosion-resistant alloy (CRA) liners are prone to wrinkling during reel-lay installation. Conventional mitigation strategies, such as increasing liner thickness or applying internal pressure, lead to higher costs and operational constraints. As an alternative to suppress wrinkling formation, this study investigates the use of an adhesive layer between the liner and the carrier pipe, referred to as an adhesive-reinforced mechanically lined pipe (ARMLP). A three-dimensional finite element model is developed to simulate a pipe with an outer diameter of 324.7 mm (12″) via hydroforming, followed by monotonic bending. The model includes geometric imperfections in the liner, a nonlinear isotropic/kinematic hardening law for both the X70 steel carrier pipe and 316L stainless steel liner, and a cohesive traction–separation law for the SikaForce® 7888 adhesive interface. The effects of residual stress from fabrication, installation pressure, and liner thickness are systematically evaluated. Simulation results show that while conventional MLPs exhibit liner wrinkling under bending, both ARMLPs and MLPs with thicker liners or installation internal pressure successfully prevent wrinkling. The adhesive layer also reduces ovalization and improves structural integrity without the need for internal pressurization. Parametric studies further suggest the potential for reducing liner thickness while maintaining performance, and mode ratio analysis reveals that the intrados is primarily subjected to pure shear, whereas the extrados exhibits predominantly mixed-mode behavior. Additionally, the presence or absence of manufacturing residual stresses has no significant impact on the ARMLP solution. These findings indicate the potential of using structural adhesives to enhance the bending response of MLPs, potentially offering a cost-effective and robust alternative for offshore pipeline installation.